阅读说明：本技术 基于弱耦合增强的石墨烯结构、石墨烯膜及光电器件 (Graphene structure based on weak coupling enhancement, graphene film and photoelectric device ) 是由 高超 彭蠡 李泠菲 方文章 刘英军 于 2020-12-30 设计创作，主要内容包括：本发明提供一种基于弱耦合增强的石墨烯结构,这种石墨烯结构通过弱耦合作用是的本体材料具有线性能带特征,促进热电子的跃迁,增加联合态密度；AB结构的存在和厚度的增加配合延长热电子弛豫时间,从而提升高能态热电子数量,同时降低了膜制备工艺的要求和成本,增加了膜制备的成功率。另外,基于石墨烯/半导体肖特基结,可以探测低能量的光,将石墨烯/硅光电器件的探测范围从可见和近红外拓展到中远红外。本发明还提供一种弱耦合增强的石墨烯光电膜,通过弱耦合实现多层石墨烯的光吸收的叠加,提高石墨烯膜的光吸收率,从而在低能量波段,热电子仍然可以积累。(The invention provides a graphene structure based on weak coupling enhancement, and the graphene structure has the advantages that a body material has linear energy band characteristics through the weak coupling effect, the transition of hot electrons is promoted, and the combined state density is increased; the existence of the AB structure and the increase of the thickness are matched to prolong the relaxation time of the hot electrons, so that the number of the high-energy-state hot electrons is increased, the requirement and the cost of a film preparation process are reduced, and the success rate of film preparation is increased. In addition, based on the graphene/semiconductor Schottky junction, low-energy light can be detected, and the detection range of the graphene/silicon photoelectric device is expanded from visible light and near infrared to middle and far infrared. The invention also provides a graphene photoelectric film with enhanced weak coupling, which realizes the superposition of light absorption of multilayer graphene through weak coupling, improves the light absorption rate of the graphene film, and can still accumulate hot electrons in a low-energy waveband.)

1. The graphene structure based on weak coupling enhancement is characterized by being formed by vertically stacking a plurality of graphene units; the graphene unit is a single-layer graphene sheet, or is formed by stacking more than two graphene sheets in an AB stacking manner; the upper graphene unit and the lower graphene unit are weakly coupled, so that hot electron transition is promoted, the electron combined state density is increased, and the number of high-energy state hot electrons is increased.

2. The graphene structure of claim 1, wherein the number of graphene layers of a single graphene unit is less than 9.

3. The graphene structure of claim 1, wherein the number of graphene layers of a single graphene unit is 1.

4. Use of the graphene structure of claim 1 for enhancing hot electron accumulation, wherein said use is: the graphene AB stacking structure is used for increasing the thermal electron relaxation time, the weak coupling structure is used for increasing the hot electron transition probability, and finally the generation and accumulation of hot electrons in a high-energy-state region are promoted.

5. A weakly coupled enhanced graphene film comprising the weakly coupled enhanced graphene-based structure of claim 1, a stacking direction of graphene units in the graphene structure being along a thickness direction of the graphene film; the graphene film enhances hot electron accumulation in high-state regions through the weakly coupled enhanced graphene-based structure.

6. The graphene film of claim 5, wherein I of the graphene film_D/I_GBelow 0.05.

7. The graphene film according to claim 5, wherein the graphene film has a non-AB structure content of 5% or more.

8. The graphene film according to claim 5, wherein the graphene oxide film is obtained by assembling a graphene oxide film from a solution, and the defect is repaired by heat treatment.

9. The graphene film of claim 8, wherein the graphene oxide film has a thickness of 20-120nm, is deposited on a rigid substrate having a porosity of greater than 60% by solution assembly, and is then peeled from the rigid substrate by: placing the substrate in a reduction chamber with HI steam for chemical reduction until the graphene oxide is automatically stripped from the substrate; in the reduction process, at least the HI concentration is more than 0.3g/L, and the water vapor concentration is less than 0.07g/L for more than 10 min.

10. The graphene membrane of claim 9, wherein the method further comprises vaporizing hydroiodic acid using a vaporization chamber in communication with the reduction chamber to deliver HI vapor to the reduction chamber.

11. The graphene film of claim 10, wherein the reduction chamber and the evaporation chamber are located in the same sealed cavity, and the evaporation chamber is located below the reduction chamber, the evaporation chamber being located in an oil or water bath at a temperature of 80-120 degrees celsius; the top of the reduction chamber is provided with a condensation zone, and the temperature of the condensation zone is 0-40 ℃.

12. The graphene film according to claim 11, wherein the condensation zone is provided with a water absorbing material that is: porous strong hydrophilic absorbent materials such as absorbent filter paper and super absorbent resin, and strong absorbent chemicals such as calcium chloride and phosphorus pentoxide.

13. The graphene film of claim 11, wherein a HI-resistant carrier rack is disposed within the reduction chamber for loading the substrate.

14. The graphene film of claim 10, wherein the reduction chamber and the evaporation chamber are each located in a sealed cavity; the two closed cavities are communicated through a condensing pipe; the temperature of the condenser pipe is 0-40 ℃; the condensation pipe condenses the water vapor evaporated by the evaporation chamber and reflows to the evaporation chamber.

15. The graphene membrane of claim 14, wherein the evaporation chamber and the reduction chamber are both in an oil or water bath at a temperature of 80-120 degrees celsius, and the reduction chamber is at a lower temperature than the evaporation chamber.

16. The graphene membrane of claim 9, wherein the substrate is an anodized aluminum, a tetrafluoroethylene filter, a fiberglass filter.

17. The graphene film according to claim 5, which is obtained by stacking graphene thin film layers grown by a CVD method and then forming a dense structure by heat treatment.

18. The graphene film according to claim 5, wherein the graphene film is obtained by assembling a graphitizable material in a solution and graphitizing the assembled material by heat treatment.

19. The graphene film of claim 18, wherein the graphitizable material comprises graphene oxide, polyimide, and mixtures of graphene oxide and non-graphitizable or low graphitizable macromolecules.

20. The graphene film according to claim 5, wherein the graphene film is obtained by catalyzing a vitrifiable small molecule with a nickel-based catalyst.

21. The use of the graphene film according to claim 5 in photoelectric conversion, wherein the graphene film promotes hot electron transition, generation and accumulation of hot electrons in a high energy state region through the weak coupling enhancement based graphene structure.

22. A graphene optoelectronic device comprising the weakly coupled enhanced graphene film of claim 5 and a semiconductor substrate, the weakly coupled enhanced graphene film being tiled on the semiconductor substrate.

23. The optoelectronic device according to claim 22, wherein the graphene film is tiled on a semiconductor substrate by: placing a graphene film on a semiconductor substrate, and dropwise adding a solvent with high surface tension on the edge of the graphene film so as to unfold the folds of the graphene film in the process that the solvent permeates from the edge of the graphene film to the inside; the solvent is then evaporated.

24. The optoelectronic device according to claim 22, wherein the high surface tension solvent includes, but is not limited to, deionized water, dmf, dmac, ethylene glycol, propylene glycol, o-xylene, toluene, butyl acetate, liquid paraffin, menthol and mixtures thereof.

25. The optoelectronic device according to claim 22, wherein after volatilizing the solvent, further sintering process; the sintering temperature is 400-1000 ℃.

26. The optoelectronic device according to claim 22, wherein the semiconductor substrate comprises: elemental semiconductors, compound semiconductors, including but not limited to one or more of Si, Ge, diamond, Sn, InP, GaAs, AlGaAs, InGaP, InGaAs, AlInGaAs, InGaAsP, AlInGaAsP, GaN, InGaN, AlGaN, AlInGaN, GaP, alloys thereof, or derivatives thereof.

27. A method of fabricating a graphene-based photovoltaic device as claimed in claim 22, comprising the steps of:

(1) firstly, reserving a working window on a semiconductor substrate, plating an insulating layer outside the working window, and then sputtering an electrode layer in the insulating layer;

(2) the method comprises the following steps of firstly, paving a multilayer graphene film on a working window, enabling the multilayer graphene film to be in contact with an electrode layer, dropwise adding an organic solvent on the edge of the graphene film, enabling the organic solvent to penetrate from the edge of the graphene film to the inside, volatilizing the solvent, and realizing the tight combination of the film and a semiconductor by utilizing the surface tension of the solvent so as to obtain an independent photoelectric device;

(3) and packaging, and connecting with the electrode layer and the semiconductor substrate of the photoelectric device by leads respectively for outputting detection signals.

28. A method for promoting hot electron transition through weak coupling effect of graphene non-AB structure.

29. A method for increasing the hot electron transition probability of a hot electron in the direction perpendicular to the transport direction of a graphene film, the method comprising at least: the number of non-AB structures in the vertical transmission direction of the graphene film is increased, and hot electron transition is promoted through the weak coupling effect of the non-AB structures.

30. A method of enhancing the accumulation of hot electrons in the direction perpendicular to the transport direction of a graphene film, the method comprising: the number of non-AB structures in the vertical transmission direction of the graphene film is increased, and the thermo-electronic transition probability is increased through the weak coupling effect of the non-AB structures; and the AB stacking structure in the vertical direction of the graphene is regulated and controlled, the thermal electron relaxation time is prolonged, and the generation and accumulation of thermal electrons in a high-energy-state region are promoted.

31. The method of claim 30, further comprising: increasing the thickness of the film within the range of less than or equal to 60 nm; the larger the thickness is, the larger the layer number is, the more hot electrons generated by light absorption and hot electron relaxation time are enhanced, the hot electron transition probability is further increased through weak coupling of a non-AB structure, and meanwhile, the graphene joint state density is increased, and the generation and accumulation of hot electrons in a high-energy state region are promoted.

Technical Field

The invention relates to a graphene functional material, in particular to a graphene structure based on weak coupling enhancement, a graphene film and a device and a material preparation method thereof.

Background

In 2010, Andre geom and konstatin novoseov, two professors of manchester university in the united kingdom, raised the worldwide hot trend of graphene research because of the first successful separation of stable graphene to obtain the nobel prize of physics. The graphene has excellent electrical properties (the electron mobility can reach 2 multiplied by 10 at room temperature)⁵cm²Vs), outstanding performance (5000W/(mK), extraordinary specific surface area (2630 m)²In g), its Young's modulus (1100GPa) and breaking strength (125 GPa). The excellent electric and heat conducting performance of the graphene completely exceeds that of metal, meanwhile, the graphene has the advantages of high temperature resistance and corrosion resistance, and the good mechanical property and the low density of the graphene enable the graphene to have the potential of replacing metal in the field of electric heating materials.

The graphene film of macroscopically assembled graphene oxide or graphene nanosheets is the main application form of nanoscale graphene, and common preparation methods are a suction filtration method, a scraping method, a spin-coating method, a spraying method, a dip-coating method and the like. Through further high-temperature treatment, the defects of graphene can be repaired, the conductivity and the thermal conductivity of the graphene film can be effectively improved, and the graphene film can be widely applied to portable electronic equipment such as sound production, sound wave detection, photoelectric detection, smart phones, intelligent portable hardware, tablet computers and notebook computers.

However, since the single-layer graphene has low absorbance and cannot absorb light of sufficient intensity, it does not have any response to electromagnetic waves in infrared, terahertz, and other lower energy bands. Therefore, researchers do a lot of work on the modification aspect of the graphene device so as to improve the absorption of the device to light. In addition, it is generally believed that single-layer graphene cannot perform effective hot electron accumulation and cannot cross the potential barrier between graphene and a semiconductor, and thus graphene does not respond significantly in a low-energy band.

The traditional Schottky junction is a metal/semiconductor structure, but the service life of photoexcited hot electrons of a metal material is extremely low (about 0.1 ps) and the noise is large, so that the Schottky junction cannot be applied to the field of normal-temperature photoelectronic devices. Compared with a metal material, the service life of the single-layer graphene thermal electron is prolonged by about one order of magnitude (1ps), normal-temperature noise is greatly inhibited, however, due to the excellent transparency of the graphene, the graphene cannot be subjected to effective thermal electron accumulation and cannot span potential barriers of the graphene and a semiconductor, and therefore, the graphene does not respond obviously in a low-energy waveband. In addition, the transfer of the single-layer graphene film is difficult, and the pollution of metal and polymer cannot be completely removed; graphene films with effective hot electron accumulation (multilayer graphene films stacked in an AB structure) have been preliminarily reported, but the hot electron accumulation efficiency is very low, which is caused by that the electronic structure of the graphene film with the AB structure is biased to be a graphite structure, the electronic state density is relatively low, the high-energy state orbit occupation capability is relatively weak, and the detection capability is relatively low.

In addition, the defect structure of the graphene often increases graphene hot electron-phonon scattering, so that in order to improve the graphene hot electron relaxation time, the defect structure must be repaired as much as possible by high-temperature treatment, and the preparation difficulty of the photoelectron detection device is increased. However, the existence of the defect state increases the device temperature, and contributes to hot electron transition and improvement of the responsivity while damaging the response speed.

Disclosure of Invention

As one aspect of the present invention, the present invention provides a graphene structure based on weak coupling enhancement, which increases electron association state density through weak coupling effect of a non-AB structure, and promotes light absorption; meanwhile, a graphene linear energy band with a non-AB structure is introduced, so that hot electron transition is promoted, and the occupation probability of high-energy-state hot electrons is improved.

As another aspect of the present invention, the present invention provides a graphene film based on weak coupling enhancement, which increases electron associated state density, increases light absorption, and promotes hot electron transition through weak coupling. The structure also reduces the requirements and the cost of the membrane preparation process and increases the success rate of membrane preparation.

As another aspect of the present invention, the present invention provides a graphene photoelectric device based on weak coupling enhancement, such as a graphene/silicon schottky junction, in which a graphene film has a zero band gap, and can absorb light with long wavelength and low energy, so that on one hand, the responsivity of the graphene/silicon photoelectric device can be improved, and on the other hand, the detection range extends from visible and near infrared to middle and far infrared bands, thereby realizing detection of a wide spectrum. The idea can also be extended to other graphene/semiconductor schottky type photodetectors (such as graphene/germanium detectors). The graphene film can also be introduced into other photoelectric detector systems (such as a photoconductive detector, a PIN detector and an avalanche detector), so that the absorption of the infrared band of the graphene film is enhanced, and the wide spectrum detection and the infrared detection are realized. Photoelectric detectors are widely used in the fields of military industry, national defense, medical treatment, biology, consumer electronics and the like. For example, infrared photoelectric detectors are needed for reconnaissance and remote sensing in military affairs; high-precision photoelectric detectors are also needed in various spectral analysis instruments used for medical detection and substance analysis to collect and extract absorption, transmission, emission spectra and the like; in the field of smart homes which are currently being developed, the wireless infrared detector plays an important role in realizing the connection and interaction of equipment. In the core technology laser radar in the current popular unmanned driving field, a high-speed and high-sensitivity photoelectric detector is also one of the core components. In terms of consumer electronics, in imaging, a photoelectric detector based on the graphene film can realize detection of a wide spectrum, so that fusion processing of a visible image and an infrared image is hopeful to be combined with a multispectral fusion technology, the details of the image are enhanced, and the definition is improved. In the medical field, photoelectric detection is also widely applied, for example, blood oxygen detection is to extract the reflection of hemoglobin to infrared light through an infrared detector on a wearable device, and micro photoelectric detection also plays an important role in the future wearable or even implantable bio-sensing field.

One object of the present invention is to provide a graphene structure based on weak coupling enhancement, which is formed by stacking a plurality of graphene units up and down; the graphene unit is a single-layer graphene sheet or is formed by stacking more than two graphene sheets, and the stacking mode is AB stacking; the upper and lower two adjacent graphene units are non-AB stacked structure areas, so that the two graphene units are weakly coupled. In the AB stacking area, the electron clouds are fused into a whole, the electronic structure of the graphene film is heavier than that of a graphite structure, the electron phonon scattering of graphene is weakened under the structure, and the thermal electron relaxation time is prolonged; in a non-AB stacking structure area, electron cloud layers are separated, and the electronic structure of the graphene film is more prone to the graphene structure, so that the electron association state density is increased, the light absorption is increased, and the hot electron transition is easy.

Another object of the present invention is to provide a graphene structure based on weak coupling enhancement, which is formed by stacking a plurality of graphene units one on top of the other; the graphene unit is a single-layer graphene sheet or is formed by stacking 2-9 graphene sheets, and the stacking mode is AB stacking; the upper and lower adjacent graphene units are weakly coupled, the combined state density is high, and the light absorption is enhanced. The lap gap (vertical direction) of the sheet layer caused by the structural unit formed by the graphene sheets within 9 layers can be controlled to be about 3nm, and hot electrons with higher combined state density can be tunneled without being influenced.

Another object of the present invention is to provide a graphene structure based on weak coupling enhancement, which is formed by stacking a plurality of graphene units one on top of the other; the graphene unit is a single-layer graphene sheet; and weak coupling is formed between the upper graphene unit and the lower graphene unit. The single-layer graphene electronic structure can effectively assist in increasing the combined state density, promoting light absorption, promoting hot electron transition and increasing the occupation probability of high-energy-state hot electrons.

As another aspect of the present invention, the present invention provides a graphene photoelectric film with enhanced weak coupling, which realizes superposition of light absorption of multilayer graphene through weak coupling, and improves light absorption rate and hot electron lifetime of the graphene film, so that hot electrons can still be accumulated in a low energy band.

Another objective of the present invention is to provide a graphene photoelectric film with enhanced weak coupling, which includes a graphene structure. The graphene structure is formed by vertically stacking a plurality of graphene units; the graphene unit is a single-layer graphene sheet or is formed by stacking more than two graphene sheets, and the stacking mode is AB stacking; and weak coupling is formed between the upper graphene unit and the lower graphene unit. The stacking direction of the graphene units in the graphene structure is along the thickness direction of the graphene film. The light irradiates the surface of the graphene film, photoelectrons pass through an AB stacking area and a non-AB stacking area from the surface, electron clouds are integrated in the AB stacking area, the electronic structure of the graphene film is heavier than that of a graphite structure, the scattering of hot electrons and phonons is weakened, and the relaxation time of the hot electrons is prolonged; in a non-AB stacking structure area, electron cloud layers are separated, the electronic structure of the graphene film is more prone to a graphene structure, the combined state density is increased, the light absorption is increased, and hot electron transition is promoted.

The invention also provides a graphene photoelectric film with enhanced weak coupling, which comprises the graphene structure. The stacking direction of the graphene units in the graphene structure is along the thickness direction of the graphene film. The non-AB structure content of the entire film is above 5%, even above 90%. A large amount of non-AB structure content enables a large amount of weak coupling action areas to exist in the graphene film, so that the overall electronic structure of the graphene film approaches to that of single-layer graphene, the combined state density is greatly increased, absorption is enhanced, hot electron transition is promoted, and the number of high-energy-state hot electrons is further increased.

In certain embodiments, I of the graphene film_D/I_GBelow 0.05. In general, defects in graphene increase scattering of graphene, so that the graphene hot electron relaxation time is reduced, but scattering of phonons by the graphene defects is reflected in the horizontal direction more and has less influence on the vertical direction; the scattering effect of the non-coupled stack of the graphene unit on the hot electrons is mainly directed to the vertical direction, so that the influence on the scattering of the hot electrons is greater, and the most practical effect is determined. In short, the existence of weak coupling action enhances the tolerance of the photoelectric effect of the graphene film to defects.

In certain embodiments, the weak coupling-enhanced graphene film is obtained after the graphene oxide film obtained by solution assembly (suction filtration, spin coating, spray coating, film spreading, and the like) is subjected to heat treatment (graphitization furnace annealing, laser heating annealing, microwave heating annealing, and the like) to repair defects.

Since the substrate is not suitable for high-temperature heat treatment, it is generally necessary to peel the graphene oxide film from the substrate and then perform heat treatment. The inventor finds that the concentration of hydriodic acid steam is insufficient in the reduction process and the relative steam pressure is low in a large number of graphene stripping experiments, and HI steam is not enough to completely permeate into a contact interface between a graphene film and a substrate; in addition, water vapor is mixed in the HI vapor to play a role in infiltration, so that the rapid permeation of HI is hindered, and the interface is infiltrated to inhibit interface separation. The contact area and the acting force of the interfacial agent are greatly reduced by the asymmetric reduction and the permeation of the hydroiodic acid, and the weak contact interface can be stripped by the action of solvents such as isopropanol and the like; however, the film was not separated from the substrate due to the wetting with water vapor and the insufficient pressure of HI vapor. In the application, a graphene film stripping method is provided for a rigid substrate with pores, and the asymmetric reduction and the interfacial permeation of HI are enhanced by regulating HI and controlling the vapor pressure of water, so that the graphene film and the substrate are gradually separated (fig. 8). The method specifically comprises the following steps: the graphene oxide film has a thickness of 20-120nm, is deposited on a rigid substrate with a porosity of more than 60% by solution assembly, and is then peeled off from the rigid substrate by the following method: placing the substrate in a reduction chamber with HI steam for chemical reduction until the graphene oxide is automatically stripped from the substrate; in the reduction process, at least the HI concentration is more than 0.3g/L, and the water vapor concentration is less than 0.07g/L for more than 10 min.

In the present application, the HI steam with low water vapor content may be directly input, or the hydriodic acid may be evaporated by using an evaporation chamber communicated with the reduction chamber to input the HI steam into the reduction chamber.

In certain embodiments, the reduction chamber and the evaporation chamber are located in the same sealed cavity, and the evaporation chamber is located below the reduction chamber, and the evaporation chamber is located in an oil bath or water bath with a temperature of 80-120 ℃; the top of the reduction chamber is a condensation zone, and the temperature of the condensation zone is controlled to be 0-40 ℃ (usually, the reduction can be carried out at room temperature). The hydroiodic acid solution evaporates into HI steam and water vapor, which condenses at the top, reducing the water vapor content in the chamber, while the condensation temperature of HI is lower, which remains gaseous. Preferably, the condensation zone is provided with a water absorbing material to absorb water vapor and condensed water, so as to prevent the condensed water from re-evaporating after falling back. As a common technical means for this collar, the water absorbing material is: porous strong hydrophilic absorbent materials such as absorbent filter paper and super absorbent resin, and strong absorbent chemicals such as calcium chloride and phosphorus pentoxide.

For convenient preparation, a HI-resistant carrier is arranged in the reduction chamber and used for loading the substrate, such as a polytetrafluoroethylene net rack, a hollow glass rack and the like.

In some embodiments, the reduction chamber and the evaporation chamber are respectively located in a closed cavity. The two closed cavities are communicated through a condensing pipe; the condensation pipe condenses the water vapor evaporated by the evaporation chamber and reflows to the evaporation chamber. The iodic acid solution evaporates into HI steam and water vapor, the water vapor condenses in the condenser tube and flows back to the evaporation chamber, and the HI, which is still in a gaseous state, has a low condensation temperature. As the common knowledge in the field, the water vapor content entering the reduction chamber can be effectively controlled by setting the length, the inclination, the condensing environment and other parameters of the condensing pipe.

Preferably, the evaporation chamber and the reduction chamber are both positioned in an oil bath or a water bath with the temperature of 80-120 ℃, and in some preferable schemes, the temperature of the reduction chamber is lower than that of the evaporation chamber, so that the rapid diffusion of hydrogen iodide gas to the reduction chamber is facilitated. Meanwhile, after hydrogen iodide is completely evaporated, pressure difference exists between two sides due to the existence of the temperature difference, and then hydrogen iodide with higher mass density is distributed in the reduction chamber of the low-temperature area.

In the present application, the substrate is an anodic alumina, a tetrafluoroethylene filter membrane, a glass fiber filter membrane, or the like.

Compared with the solid phase transfer preparation method, the gas phase separation method is milder, hardly has any strong tearing effect on the film, and the solid phase transfer method is opposite. The concrete expression is as follows: firstly, AAO is a brittle material, and a solid phase transfer agent has a weight burden on the AAO during operation, and may damage an AAO film or fail to have perfect covering continuity, resulting in discontinuity of solid phase transfer agent peeling, and finally failing to obtain a complete graphene nano film (fig. 9); the gas-phase reduction does not have the problems, so that a perfect large-size graphene film can be obtained. On the microstructure, the solid phase transfer method may cause strong adhesion between graphene oxide and the AAO substrate due to insufficient reduction degree of graphene, and form hole-type tearing in a local area under the action of cold shrinkage (fig. 10a 1-a 2), while the mild gas phase transfer method does not have the problem, and can obtain a perfect graphene film without any tearing (fig. 10B-D). Generally, when the solid phase transfer method is used for separation, an experimenter needs to perform fine operation, if the operation is improper and the attention is not focused, the graphene nano-film is very easy to be damaged, and especially, local hole damage is caused in the cold-grasping process of a transfer agent, as shown in fig. 10a 1-a 2. In addition, the graphene and the substrate are still partially adhered. Macroscopically, due to uneven temperature or transfer agent deposition, local stress distribution is uneven, the shrinkage and grabbing of the solid phase transfer agent are uneven, and a complete large-size graphene film (10A1) cannot be obtained; microscopically, due to some tiny adhesion or uneven reduction, the part of graphene cannot be effectively stripped in the grabbing process, so that tiny holes can be formed, the material is uneven, and the performance stability of the material under the application scene is influenced.

In some embodiments, the graphene thin film layer grown by the CVD method is stacked and then subjected to a heat treatment (e.g., annealing in a graphitization furnace, laser heating annealing, microwave heating annealing, etc.) to form a dense structure, thereby obtaining the weak coupling enhanced graphene film.

In certain embodiments, the weakly coupled enhanced graphene film is obtained by solution assembly of graphitizable materials and graphitization thereof by thermal treatment (graphitization furnace annealing, laser heating annealing, microwave heating annealing, etc.). The graphitizable material comprises polyimide, polyacrylonitrile and asphalt.

In certain embodiments, the weakly coupled enhanced graphene membrane is obtained by catalyzing a vitrifiable small molecule (glucose, menthol, naphthalene, anthracene, etc.) with a nickel-based catalyst.

In some embodiments, a mixture of graphene oxide, polyimide, graphene oxide and a non-graphitizable or low-graphitizable polymer (e.g., a linear conjugated structure system such as pitch, lignin, poly-benzene ring structures such as polymerized and natural polycyclic aromatic hydrocarbons, and polyacrylonitrile; a mixing mass ratio is less than 1: 6 (conventionally, the carbon yield of graphene oxide is 66%, and the carbon yield of the polymer after graphitization is 50% or less.) the more benzene ring structures, the smaller the maximum mixing ratio). The mixture is characterized in that graphene can be used as a template to induce low-graphitization or non-graphitization macromolecules to be orderly arranged and graphitized along a graphene plane; meanwhile, the functional group on the surface of the oxidized graphene can provide oxygen atoms for the polyimide, polyacrylonitrile and other polymers needing to be pre-oxidized, so that the core-shell phenomenon in the pre-oxidation process of the material is avoided, the uniform pre-oxidation of the material is ensured, and the uniformity of the material structure in the high-temperature process is further ensured; furthermore, the method avoids the requirement of high orientation in the polymer graphitization process and reduces the polymer graphitization process conditions. The number of the graphene effective catalytic graphitization atoms is 4, the number of the graphene effective catalytic graphitization atoms is two, namely, the number of the graphene effective catalytic graphitization atoms is more than four, and the defects are more after high-temperature catalysis. As the matching of the conjugated structure of the polymer is weakened, the catalytic effect is weakened.

The invention also provides a graphene-based photoelectric device which comprises the graphene film with the enhanced weak coupling and a semiconductor substrate, wherein the graphene film realizes the superposition of light absorption through the weak coupling, and the light absorption rate of the graphene film is improved, so that hot electrons can still be accumulated in a low-energy waveband, and the hot electrons in a high-energy state area can cross a graphene/semiconductor potential barrier and finally obtain a collectable electric signal.

The invention also provides a graphene-based photoelectric device which comprises the graphene film with the enhanced weak coupling and a semiconductor substrate, wherein the graphene film contains the graphene structure with the enhanced weak coupling. The graphene structure with the weak coupling enhancement is formed by vertically stacking a plurality of graphene units; the graphene unit is a single-layer graphene sheet or is formed by stacking more than two graphene sheets, and the stacking mode is AB stacking; and weak coupling is formed between the upper graphene unit and the lower graphene unit. The stacking direction of the graphene units in the graphene structure is along the thickness direction of the graphene film. Photoelectrons jump into the semiconductor layer from the surface through the AB stacking area and the non-AB stacking area, wherein the AB stacking area and the electron cloud are integrated, the electronic structure of the graphene film is heavier than that of graphite, and the relaxation time of the graphene hot electrons in the structure is prolonged; in a non-AB stacking structure area, electron cloud layers are separated, the electronic structure of the graphene film is more prone to a graphene structure, the density of combined states is increased, and the light absorption in an infrared region is increased, so that hot electron transition is promoted, and more and higher-energy-state hot electrons are transited from graphene to a semiconductor.

The graphene film is tiled on a semiconductor substrate by the following method: placing a graphene film on a semiconductor substrate, and dropwise adding a solvent with high surface tension on the edge of the graphene film so as to unfold the folds of the graphene film in the process that the solvent permeates from the edge of the graphene film to the inside; the solvent is then evaporated.

In the present invention, the high surface tension solvent includes deionized water, dmf, dmac, ethylene glycol, propylene glycol, o-xylene, toluene, butyl acetate and mixtures thereof.

Preferably, after the solvent is volatilized, the sintering treatment is further performed. The sintering temperature is 400-1000 ℃ to construct a graphene-semiconductor interface, so that the dark current is further reduced.

The semiconductor substrate of the present invention comprises: elemental semiconductors, compound semiconductors, including but not limited to one or more of Si, Ge, C, Sn, GaAs, InP, AlGaAs, InGaP, InGaAs, AlInGaAs, InGaAsP, AlInGaAsP, GaN, InGaN, AlGaN, AlInGaN, GaP, alloys thereof, or derivatives thereof.

Another object of the present invention is to provide a method for manufacturing a graphene-based photovoltaic device, comprising the steps of:

(1) firstly, reserving a working window on a semiconductor substrate, plating an insulating layer outside the working window, and then sputtering an electrode layer in the insulating layer;

(2) the method comprises the following steps of firstly, paving a multilayer graphene film on a working window, enabling the multilayer graphene film to be in contact with an electrode layer, dropwise adding an organic solvent on the edge of the graphene film, enabling the organic solvent to penetrate from the edge of the graphene film to the inside, volatilizing the solvent, and realizing the tight combination of the film and a semiconductor by utilizing the surface tension of the solvent so as to obtain an independent photoelectric device;

(3) and packaging, and connecting with the electrode layer and the semiconductor substrate of the photoelectric device by leads respectively for outputting detection signals.

The invention also provides a method for increasing the hot electron transition probability of hot electrons in the direction perpendicular to the transmission direction of the graphene film, which at least comprises the following steps: the number of non-AB structures in the direction perpendicular to the transmission direction of the graphene film is increased, and hot electron transition is promoted through the weak coupling effect of the non-AB structures.

The invention also provides a method for enhancing the accumulation of hot electrons in the direction perpendicular to the transmission direction of the graphene film, which at least comprises the following steps: the number of non-AB structures in the vertical transmission direction of the graphene film is increased, and the thermo-electronic transition probability is increased through the weak coupling effect of the non-AB structures; and the AB stacking structure in the vertical direction of the graphene is regulated and controlled, the thermal electron relaxation time is prolonged, and the generation and accumulation of thermal electrons in a high-energy-state region are promoted.

Further, the method further comprises: increasing the thickness of the film within the range of less than or equal to 60 nm; the larger the thickness is, the larger the layer number is, the light absorption and the hot electron relaxation time are also enhanced, the more hot electrons are generated, the further weak coupling of a non-AB structure increases the hot electron transition probability, and meanwhile, the graphene joint state density is increased, and the generation and accumulation of hot electrons in a high-energy state region are promoted. When the thickness is more than 60nm, too high thickness will also increase the recombination of hot electrons and reduce the number of transition barrier hot electrons.

Drawings

FIG. 1 is an xps spectrum plot of two graphene films prepared in example 1;

fig. 2 is a raman plot of two graphene films prepared in example 1;

FIG. 3 is a TEM image of two graphene films prepared in example 1;

fig. 4 is an electron diffraction pattern of two graphene films prepared in example 1;

fig. 5 is a graph of the thermal electron relaxation times for two graphene films prepared in example 1.

FIG. 6 is a graph of electron diffraction patterns and corresponding electron lifetimes after different temperature treatments

Fig. 7 is a schematic diagram of superposition of light absorption by multilayer graphene through weak coupling.

FIG. 8 is a diagram of a process for stepwise separation of a graphene membrane and a substrate;

FIG. 9 is a graphene oxide membrane (4 inches) obtained by suction filtration on a rigid anodised aluminium filter membrane.

Fig. 10 is a graphene oxide film (4 inches) after separation. Wherein, the A1 diagram is the graphene nano-film assisted by the solid phase transfer agent. B1-D1 show that the transfer agent-free method is used for preparing the unbroken graphene nano film (which corresponds to the embodiment 2-4 in sequence); A2-D2 are corresponding enlarged views.

FIG. 11 is a schematic plan view A and a schematic perspective view B of the separation apparatus according to example 2;

FIG. 12 is a diagram of a separation apparatus in example 3;

FIG. 13 is a diagram of a separation apparatus in example 4.

Detailed Description

The following description is provided to disclose the invention so as to enable any person skilled in the art to practice the invention. The preferred embodiments in the following description are given by way of example only, and other obvious variations will occur to those skilled in the art. The underlying principles of the invention defined in the following description may be applied to other embodiments, variations, modifications, equivalents, and other technical solutions without departing from the spirit and scope of the invention.

In the following examples, I_D/I_GThe test method (2) is as follows: the film is transferred to a silicon substrate, and Raman full-wave band test is carried out under the full power by using 532 laser as a light source to obtain a Raman spectrum comprising a D peak, a G peak and a 2D peak. The areas defining the D and G peaks are the intensities I of the D and G peaks, respectively_D、I_GIs divided to obtain I_D/I_G。

In the following examples, the AB structure content was tested as follows: measuring the depth of stacking order in graph by Raman spectroscopy, Carbon,2008,46(2), 272-.

The single-layer graphene or the multiple layers of AB-stacked graphene can present a set of diffraction patterns (uniformly distributed on the same circumference) formed by 6 diffraction spots, and the higher the number of AB-stacked graphene layers is, the higher the spot brightness is; the presence of non-AB structures can result in sets of non-overlapping spots in the diffraction pattern. Based on this, in the following examples, the prepared thin film was placed under a high-resolution TEM to collect an electron diffraction pattern, and a vertical stack structure was tested according to the diffraction pattern. On the one hand, the number of structural units in the film can be calculated by the number of sets of diffraction spots; on the other hand, the number of stacked layers of each structural unit can be estimated from the ratio of the luminance value of the diffraction spot to the diffraction luminance of the single-layer graphene.

The weak coupling effect refers to an electron cloud coupling effect brought by disordered stacking among graphene sheets, at the moment, the electron cloud among the sheets does not achieve a complete coupling effect, and the interlayer spacing is 0.334-0.36 nm; and the coupling strength of the electron cloud orbits between graphene sheet layers under the AB stacking structure is the maximum, the interlayer spacing is 0.334nm, and the strong coupling effect is called.

According to the invention, the graphene unit is a single-layer graphene sheet or is formed by stacking 2-9 graphene sheets, the number of graphene units in the vertical direction in the graphene film can be obtained by measuring the total thickness of the graphene film and dividing the thickness of the single-layer graphene, and meanwhile, the number of layers of the graphene sheets in the single graphene unit can be obtained by measuring and calculating AB structure content by a Raman method and by an averaging method.

Example 1: weak coupling enhanced computation

The thin film with the same thickness is prepared in the embodiment, and the influence of the structural transformation of the graphene film on the thermal electron relaxation time and the photoelectric detection is verified on the premise that the defects are all approximately equal to 0. The preparation method comprises the following steps:

non-AB structure graphene films: preparing a 24nm thin film from graphene oxide by a spin coating method, and heating to 2000 ℃ at a speed of 10 ℃ per minute for 16 hours. The content of the non-AB structure is approximately equal to 100%, the number of the graphene structural units in the vertical direction is 30, and the number of graphene sheets in a single graphene structural unit is 1.

AB structure graphene film: the graphene oxide is prepared into a 24nm film by a spin coating method, and the film is heated to 2800 ℃ at a speed of 10 ℃ per minute for 2 hours.

As shown in fig. 1, after high temperature sintering, oxygen of both materials had completely disappeared, and no O signal peak was detected in the xps spectrum. On the basis, the patent uses a Raman method to characterize the sp3 structural content and the stacking mode of the film. As shown in fig. 2, neither D peak is visible, indicating that neither sp3 structure is present; the 2D peak has obvious difference, and the 2D peak of the film with high AB structure content has stronger asymmetry.

The TEM test result and the Raman test result are completely consistent. As shown in fig. 3, the electron diffraction surface of the graphene film with AB structure is formed by stacking only two structural units, wherein the speckle brightness of one structural unit is significantly higher than that of the second structural unit, that is, one of the two structural units has extremely high thickness and a very small number of layers, and the two structural units are stacked in a non-AB manner. The graphene film with the non-AB structure has a larger set number of diffraction spots (figure 4) and even forms an amorphous diffraction ring, which shows that the film is formed by stacking a large number of structural units in a non-AB form.

Based on the above structure, this patent tested the hot electron relaxation times of both. As shown in fig. 5, at the same excitation time of 200fs, the hot electron relaxation time of the graphene film having the AB structure reaches 25ps, while the hot electron relaxation time of the graphene film having the non-AB structure is maintained within 10 ps. Therefore, the graphene units are weakly coupled, the structure of the graphene units is more biased to a single-layer graphene unit, the combined state density can be increased, and the number of high-energy-state hot electrons can be increased.

The photoelectric device is manufactured by the two graphene films prepared according to the following steps:

(1) firstly, reserving a working window on a Si substrate, plating an insulating layer outside the working window, and then sputtering a Pt electrode layer in the insulating layer;

(2) firstly, laying a graphene film on a working window, contacting with an electrode layer, dripping ethylene glycol at the edge of the graphene film, allowing the ethylene glycol to permeate from the edge of the graphene film to the inside, volatilizing a solvent, and realizing the tight combination of the film and a semiconductor by utilizing the surface tension of the solvent so as to obtain an independent photoelectric device;

(3) and packaging, and connecting with the electrode layer and the semiconductor substrate of the photoelectric device by leads respectively for outputting detection signals.

The electrode and the semiconductor of the device are tested by applying a reverse bias voltage (silicon end is grounded) of-2V to-1V by using a keithley source table; after being connected with the amplifying circuit, the detection data can be obtained by connecting with an oscilloscope as shown in the following table 1.

TABLE 1

Example 2

Step 1: preparing graphene oxide obtained by a hummer method into a graphene oxide aqueous solution with the concentration of 0.5ug/mL, and performing suction filtration to form a film by using a rigid tetrafluoroethylene filter membrane with the porosity of 60% as a substrate, wherein the graphene oxide film has the thickness of 100nm and the area of 80 +/-5 cm²。

In this embodiment, a device as shown in fig. 11A-B is used to strip a graphene oxide film, the device includes a cylindrical cavity 3, a hydroiodic acid solution 2 is contained in the cavity 3, a polytetrafluoroethylene net frame 2 is fixed above the liquid level of the hydroiodic acid solution, and a water-absorbing filter paper 5 is arranged on a top cover 4 for sealing the cylindrical cavity.

The lower part of the cylindrical cavity is positioned in a water bath 1 at 80 ℃, and a sample to be peeled is placed on a polytetrafluoroethylene net rack 2.

The hydroiodic acid solution is evaporated under heating into HI steam and water vapor, which condenses on the top and is absorbed by the absorbent filter paper, to reduce the water vapor content in the chamber, while the HI remains in the gaseous state at a lower condensation temperature.

In this embodiment, the cylindrical cavity 3 has a volume of 1L and a bottom area of 120cm². The hydriodic acid solution in the chamber 3 had a mass concentration of 50%, the HI content was 0.42g by mass, and the remainder was water (0.42 g). The absorbent filter paper (2g) had a water absorption limit of 60% of its mass. Upper part of the cavity 3The ambient temperature is 0 degrees celsius.

After heating for 5 minutes, the hydriodic acid solution 2 was completely evaporated and the contained hydrogen iodide solution was visually reduced to be invisible. The condensation of partial water drops is seen on the top layer, and the absorbent paper absorbs moisture and expands. The weight of the water absorption filter paper is increased by 0.44g through a sampling test, and the concentration of the hydriodic acid is still maintained at 0.33g/L through an acid-base test through gas sampling at the moment. It was confirmed that the water vapor content in the cavity 3 was 0.07g/L or less. After the duration of 1 hour, the acid-base test is carried out by gas sampling, and the concentration of the hydroiodic acid is still maintained at 0.32 g/L.

In order to avoid the influence of the above sampling measurement on the graphene film, the same apparatus is additionally provided in this example, the same graphene oxide film is directly peeled off without sampling the water-absorbing filter paper (2g) and sampling the gas in the chamber, the processing time is 4h, and after 4h, the graphene is separated, as shown in fig. 10B 1-B2. It can be seen from the figure that under the reduction action of hydroiodic acid, the graphene film is completely separated from the substrate under the action of stress, and no macroscopic damage or microscopic holes appear in the separation process.

3 graphene films were prepared according to step 1.

Step 2: the 3 sample films are respectively annealed by a graphitization furnace at 1600 ℃, 1800 ℃ and 2000 ℃ for 2 h.

By Raman testing, it I_D/I_GAnd non-AB structure content as in table 2;

as shown in A1-A3 of FIG. 6, it was determined by TEM electron diffraction vs. vertical stacking structure test and analysis as in example 1: the three graphene films comprise a large number of graphene structures with weak coupling effect; the graphene film is formed by stacking a plurality of graphene units up and down; the graphene unit is formed by stacking single-layer graphene sheets in a disordered manner; and weak coupling is formed between the upper graphene unit and the lower graphene unit.

Under the excitation time of 200fs, the thermal electron relaxation time of the graphene film is as shown in B1-B3 of FIG. 6, and is not shorter than 5 ps.

The prepared graphene film is used for manufacturing a photoelectric device according to the following steps:

(1) firstly, reserving a working window on a Si substrate, plating an insulating layer outside the working window, and then sputtering a Pt electrode layer in the insulating layer;

(2) firstly, laying a graphene film on a working window, contacting with an electrode layer, dripping ethylene glycol at the edge of the graphene film, allowing the ethylene glycol to permeate from the edge of the graphene film to the inside, volatilizing a solvent, and realizing the tight combination of the film and a semiconductor by utilizing the surface tension of the solvent so as to obtain an independent photoelectric device;

(3) and packaging, and connecting with the electrode layer and the semiconductor substrate of the photoelectric device by leads respectively for outputting detection signals.

The electrode and the semiconductor of the device are tested by applying a reverse bias voltage (silicon end is grounded) of-2V to-1V by using a keithley source table; after being connected with the amplifying circuit, the detection data can be obtained by connecting with an oscilloscope as shown in the following table 2.

TABLE 2

Example 3

(1) Preparing graphene oxide obtained by a hummer method into a graphene oxide aqueous solution with the concentration of 0.5ug/mL, and performing suction filtration to form a film by using a rigid anodic alumina filter membrane with the porosity of 80% as a substrate, wherein the graphene oxide film has the thickness of 60nm and the area of 80 +/-5 cm²。

In this embodiment, the graphene oxide film is peeled off using an apparatus as shown in fig. 12, which includes two chambers 11 and 12 on the left and right. The chambers 11 and 12 communicate with each other through an inclined condensing duct 13. Both chambers 11 and 12 are placed in a water bath 14 at 80 degrees celsius.

The cavity 11 is filled with hydriodic acid solution, and the cavity 12 is used for placing the graphene oxide film to be stripped. The hydriodic acid solution in the cavity 11 is volatilized, the water vapor in the hydriodic acid solution is condensed and flows back to the cavity 11 in the condensation pipe, the condensation temperature of HI is higher, and the HI is input into the cavity 12 through the condensation pipe 13 to construct an environment with high HI concentration and low water vapor concentration in the cavity 12.

In this embodiment, the cavities 11 and 12 have a volume of 400mL and a bottom area of 50cm². The content of the hydroiodic acid solution in the cavity 11 is 0.5g (the HI mass concentration is 55%), the ambient temperature of the condensation pipe 13 is 40 ℃, the length of the condensation pipe is 20cm, and the inclination angle is 30 ℃, so that the construction of the environment with high HI concentration and low water vapor concentration in the cavity 12 can be effectively ensured.

Experiments prove that after heating for 5 minutes, the hydriodic acid solution is completely evaporated, water vapor is condensed and flows back to the cavity 11 at the front part of the condensation pipe, no condensed water is generated at the rear part of the condensation pipe, and the fact that almost no water vapor enters the reduction chamber at the right side is shown. After the gas in the reduction chamber is sampled and subjected to acid-base tests, the concentration of the hydroiodic acid is still kept at 0.43 g/L.

After 30 minutes, the evaporation chamber on the right keeps evaporation-condensation reflux, no condensed water is generated at the rear part of the condensation pipe, and the concentration of the hydroiodic acid is still kept to be 0.41g/L after the gas sampling of the reduction chamber is carried out.

In order to avoid the influence of the sampling measurement on the graphene film, the same device is additionally provided in the present embodiment, the gas in the cavity is not sampled, the same graphene oxide film is directly stripped, and after 1 hour of reduction, the graphene is separated, as shown in fig. 10C1 to C2. It can be seen from the figure that under the reduction action of hydroiodic acid, the graphene film is completely separated from the substrate under the action of stress, and no macroscopic damage or microscopic holes appear in the separation process.

(2) Annealing for 0.5h in a graphitization furnace at 2000 ℃.

By Raman testing, it I_D/I_G0.05, the content of non-AB structure is about 100 percent; the content of the non-AB structure is approximately equal to 100%, the number of the graphene structural units in the vertical direction is 60, and the number of graphene sheets in a single graphene structural unit is 1.

Testing the vertical stacking structure through TEM electron diffraction, wherein the graphene film comprises a large number of graphene structures with weak coupling effect; the graphene film is formed by stacking a plurality of graphene units up and down; the graphene unit is formed by stacking single-layer graphene sheets in a disordered manner; and weak coupling is formed between the upper graphene unit and the lower graphene unit.

The prepared graphene film is used for manufacturing a photoelectric device according to the following steps:

(1) firstly, reserving a working window on a Si substrate, plating an insulating layer outside the working window, and then sputtering a Pt electrode layer in the insulating layer;

(2) firstly, laying a graphene film on a working window, contacting with an electrode layer, dripping ethylene glycol at the edge of the graphene film, allowing the ethylene glycol to permeate from the edge of the graphene film to the inside, volatilizing a solvent, and realizing the tight combination of the film and a semiconductor by utilizing the surface tension of the solvent so as to obtain an independent photoelectric device;

(3) and packaging, and connecting with the electrode layer and the semiconductor substrate of the photoelectric device by leads respectively for outputting detection signals.

Applying a reverse bias voltage of-2V to-1V on an electrode and a semiconductor of the device by utilizing a keithley source table for testing; after being connected with the amplifying circuit, the detection circuit is connected with an oscilloscope, and then the detection data can be obtained.

The graphene layer was irradiated with infrared light having a wavelength of 1um and a power of 5mW, and a photocurrent signal of 1.1mA was measured within 20 ns.

The graphene layer was illuminated with infrared light of wavelength 4um and power 20mW and a photocurrent signal of 97uA was measured in 25 ns.

The graphene layer was irradiated with infrared light having a wavelength of 10.6um and a power of 50mW, and a photocurrent signal of 8.3uA was measured in 80 ns.

Example 4

(1) Preparing graphene oxide obtained by a hummer method into a graphene oxide aqueous solution with the concentration of 0.5ug/mL, and performing suction filtration to form a film by taking a rigid anodic alumina filter membrane with the porosity of 80% as a substrate, wherein the graphene oxide film has the thickness of 60nm and the area of 80 +/-5 cm²，。

In this embodiment, the graphene oxide film is peeled off using an apparatus as shown in fig. 13, which includes two chambers 11 and 12 on the left and right. The chambers 11 and 12 communicate with each other through an inclined condensing duct 13. The chamber 11 was placed in a 120 ℃ oil bath 14 and the chambers 12 were both placed in an 80 ℃ water bath 14.

The cavity 11 is filled with hydriodic acid solution, and the cavity 12 is used for placing the graphene oxide film to be stripped. The hydriodic acid solution in the cavity 11 is volatilized, the water vapor in the hydriodic acid solution is condensed and flows back to the cavity 11 in the condensation pipe, the condensation temperature of HI is higher, and the HI is input into the cavity 12 through the condensation pipe 13 to construct an environment with high HI concentration and low water vapor concentration in the cavity 12.

In this example, the volumes of the chambers 11 and 12 were 400mL and the bottom area was 50cm, as in example 2². The content of the hydroiodic acid solution in the cavity 11 is 0.3g (the HI mass concentration is 55%), the ambient temperature of the condensation pipe 13 is 20 ℃, the length of the condensation pipe is 20cm, the inclination is 30 ℃, and the construction of the environment with high HI concentration and low water vapor concentration in the cavity 12 can be effectively guaranteed.

Experiments prove that after heating for 5 minutes, the hydriodic acid solution is completely evaporated, water vapor is condensed and flows back to the cavity 11 at the front part of the condensation pipe, no condensed water is generated at the rear part of the condensation pipe, and the fact that almost no water vapor enters the reduction chamber at the right side is shown. After the gas in the reduction chamber is sampled and subjected to acid-base tests, the concentration of the hydroiodic acid is still kept at 0.33 g/L.

After 10 minutes, the evaporation-condensation reflux of the evaporation chamber on the right side is kept, no condensed water is still generated at the rear part of the condensation pipe, and the concentration of the hydroiodic acid is still kept to be 0.30g/L after the gas sampling of the reduction chamber is carried out.

In order to avoid the influence of the sampling measurement on the graphene film, the same device is additionally provided in the present embodiment, the gas in the cavity is not sampled, the same graphene oxide film is directly stripped, and after 2 hours of reduction, the graphene is separated, as shown in fig. 10D1 to D2. It can be seen from the figure that under the reduction action of hydroiodic acid, the graphene film is completely separated from the substrate under the action of stress, and no macroscopic damage or microscopic holes appear in the separation process.

(2) Annealing for 12h in a graphitization furnace at 2000 ℃.

By Raman testing, it I_D/I_G0.003, the content of non-AB structure is about 100 percent; the number of the graphene structural units in the vertical direction is 60, and single grapheneThe number of graphene sheets in the structural unit is 1.

Testing the vertical stacking structure through TEM electron diffraction, wherein the graphene film comprises a large number of graphene structures with weak coupling effect; the graphene film is formed by stacking a plurality of graphene units up and down; the graphene unit is formed by stacking single-layer graphene sheets in a disordered manner; and weak coupling is formed between the upper graphene unit and the lower graphene unit.

The prepared graphene film is used for manufacturing a photoelectric device according to the following steps:

(1) firstly, reserving a working window on a Si substrate, plating an insulating layer outside the working window, and then sputtering a Pt electrode layer in the insulating layer;

(2) firstly, laying a graphene film on a working window, contacting with an electrode layer, dripping ethylene glycol at the edge of the graphene film, allowing the ethylene glycol to permeate from the edge of the graphene film to the inside, volatilizing a solvent, and realizing the tight combination of the film and a semiconductor by utilizing the surface tension of the solvent so as to obtain an independent photoelectric device;

(3) and packaging, and connecting with the electrode layer and the semiconductor substrate of the photoelectric device by leads respectively for outputting detection signals.

Applying a reverse bias voltage of-2V to-1V on an electrode and a semiconductor of the device by utilizing a keithley source table for testing; after being connected with the amplifying circuit, the detection circuit is connected with an oscilloscope, and then the detection data can be obtained.

The graphene layer was irradiated with infrared light having a wavelength of 1um and a power of 5mW, and a photocurrent signal of 1.13mA was measured within 20 ns.

The graphene layer was irradiated with infrared light having a wavelength of 4um and a power of 20mW, and a photocurrent signal of 99uA was measured in 25 ns.

The graphene layer was irradiated with infrared light having a wavelength of 10.6um and a power of 50mW, and a photocurrent signal of 8.1uA was measured in 80 ns.

Example 5

(1) Preparing the graphene oxide obtained by the hummer method into a graphene oxide aqueous solution with the concentration of 0.5ug/mL, and performing suction filtration to form a film by taking anode alumina as a substrate, wherein the number of graphene atomic layers is 120.

In the embodiment, the existing solid transfer agent is adopted to finely transfer the graphene oxide film deposited on the anodic aluminum oxide under the scene, and the finished independent self-supporting film is obtained after multiple attempts.

(2) Annealing for 4h in a graphitization furnace at 2300 ℃.

By Raman testing, it I_D/I_GIs approximately equal to 0 (below a Raman detection line), and the content of the non-AB structure is 50 percent; the number of the graphene structural units in the vertical direction is 60, and the number of graphene sheets in a single graphene structural unit is 2.

Testing the vertical stacking structure through TEM electron diffraction, wherein the graphene film comprises a large number of graphene structures with weak coupling effect; the graphene film is formed by stacking a plurality of graphene units up and down; the graphene unit is formed by stacking single-layer graphene sheets in a disordered manner; and weak coupling is formed between the upper graphene unit and the lower graphene unit.

The prepared graphene film is used for manufacturing a photoelectric device according to the following steps:

(1) firstly, reserving a working window on a Si substrate, plating an insulating layer outside the working window, and then sputtering a Pt electrode layer in the insulating layer;

(2) firstly, laying a graphene film on a working window, contacting with an electrode layer, dripping ethylene glycol at the edge of the graphene film, allowing the ethylene glycol to permeate from the edge of the graphene film to the inside, volatilizing a solvent, and realizing the tight combination of the film and a semiconductor by utilizing the surface tension of the solvent so as to obtain an independent photoelectric device;

(3) and packaging, and connecting with the electrode layer and the semiconductor substrate of the photoelectric device by leads respectively for outputting detection signals.

Applying a reverse bias voltage of-2V to-1V on an electrode and a semiconductor of the device by utilizing a keithley source table for testing; after being connected with the amplifying circuit, the detection circuit is connected with an oscilloscope, and then the detection data can be obtained.

The graphene layer was irradiated with infrared light having a wavelength of 1um and a power of 5mW, and a photocurrent signal of 1.3mA was measured within 20 ns.

The graphene layer was illuminated with infrared light of wavelength 4um and power 20mW and a photocurrent signal of 122mA was measured in 25 ns.

The graphene layer was irradiated with infrared light having a wavelength of 10.6um and a power of 50mW, and a photocurrent signal of 10uA was measured within 80 ns.

Example 6

(1) Preparing the graphene oxide obtained by the hummer method into a graphene oxide aqueous solution with the concentration of 0.5ug/mL, and performing suction filtration to form a film by taking anode alumina as a substrate, wherein the number of graphene oxide atomic layers is 120.

In the embodiment, the existing solid transfer agent is adopted to finely transfer the graphene oxide film deposited on the anodic aluminum oxide under the scene, and the finished independent self-supporting film is obtained after multiple attempts.

(2) Annealing for 2h in a graphitization furnace at 2800 ℃.

By Raman testing, it I_D/I_GIs approximately equal to 0, and the AB structure content is 90 percent; the number of the graphene structural units in the vertical direction is 13, and the number of graphene sheets in a single graphene structural unit is 9.

Testing the vertical stacking structure through TEM electron diffraction, wherein the graphene film comprises a large number of graphene structures with strong coupling effect; the graphene film is formed by stacking a small number of graphene units up and down; the graphene unit is formed by stacking single-layer graphene sheets in an AB structure mode; and weak coupling is formed between the upper graphene unit and the lower graphene unit.

The prepared graphene film is used for manufacturing a photoelectric device according to the following steps:

(1) firstly, reserving a working window on a Si substrate, plating an insulating layer outside the working window, and then sputtering a Pt electrode layer in the insulating layer;

(2) firstly, laying a graphene film on a working window, contacting with an electrode layer, dripping ethylene glycol at the edge of the graphene film, allowing the ethylene glycol to permeate from the edge of the graphene film to the inside, volatilizing a solvent, and realizing the tight combination of the film and a semiconductor by utilizing the surface tension of the solvent so as to obtain an independent photoelectric device;

(3) and packaging, and connecting with the electrode layer and the semiconductor substrate of the photoelectric device by leads respectively for outputting detection signals.

Applying a reverse bias voltage of-2V to-1V on an electrode and a semiconductor of the device by utilizing a keithley source table for testing; after being connected with the amplifying circuit, the detection circuit is connected with an oscilloscope, and then the detection data can be obtained.

The graphene layer was irradiated with infrared light having a wavelength of 1um and a power of 5mW, and a photocurrent signal of 1.1mA was measured within 20 ns.

A photocurrent signal of 113uA was measured within 25ns by irradiating the graphene layer with infrared light having a wavelength of 4um and a power of 20 mW.

The graphene layer was irradiated with infrared light having a wavelength of 10.6um and a power of 50mW, and a photocurrent signal of 9uA was measured in 80 ns.

Example 7

(1) And removing the substrate of the single-layer graphene prepared by the copper-based CVD method by using a hydrogen evolution method, and stacking the graphene layer by layer until the number of graphene atomic layers is 150.

(2) Annealing for 12h in a graphitization furnace at 2000 ℃.

By Raman testing, it I_D/I_G0.003, the content of non-AB structure is about 100 percent; the number of the graphene structural units in the vertical direction is 150, and the number of graphene sheets in a single graphene structural unit is 1.

Testing the vertical stacking structure through TEM electron diffraction, wherein the graphene film comprises a large number of graphene structures with weak coupling effect; the graphene film is formed by stacking a plurality of graphene units up and down; the graphene unit is formed by stacking single-layer graphene sheets in a disordered manner; and weak coupling is formed between the upper graphene unit and the lower graphene unit.

The prepared graphene film is used for manufacturing a photoelectric device according to the following steps:

(1) firstly, reserving a working window on a Si substrate, plating an insulating layer outside the working window, and then sputtering a Pt electrode layer in the insulating layer;

(2) firstly, laying a graphene film on a working window, contacting with an electrode layer, dripping ethylene glycol at the edge of the graphene film, allowing the ethylene glycol to permeate from the edge of the graphene film to the inside, volatilizing a solvent, and realizing the tight combination of the film and a semiconductor by utilizing the surface tension of the solvent so as to obtain an independent photoelectric device;

(3) and packaging, and connecting with the electrode layer and the semiconductor substrate of the photoelectric device by leads respectively for outputting detection signals.

Applying a reverse bias voltage of-2V to-1V on an electrode and a semiconductor of the device by utilizing a keithley source table for testing; after being connected with the amplifying circuit, the detection circuit is connected with an oscilloscope, and then the detection data can be obtained.

The graphene layer was illuminated with infrared light of wavelength 1um and power 5mW and a photocurrent signal of 4mA was measured in 20 ns.

The graphene layer was illuminated with infrared light of wavelength 4um and power 20mW and a photocurrent signal of 160uA was measured in 25 ns.

The graphene layer was irradiated with infrared light having a wavelength of 10.6um and a power of 50mW, and a photocurrent signal of 15uA was measured within 80 ns.

Example 8

(1) And removing the substrate of the single-layer graphene prepared by the copper-based CVD method by using a hydrogen evolution method, and stacking the graphene layer by layer until the number of graphene atomic layers is 150.

(2) Annealing for 2h in a graphitization furnace at 2800 ℃.

By Raman testing, it I_D/I_G0 is approximately covered, and the AB structure content is approximately covered by 50 percent; the number of the graphene structural units in the vertical direction is 75, and the number of graphene sheets in a single graphene structural unit is 2.

Testing the vertical stacking structure through TEM electron diffraction, wherein the graphene film comprises a large number of graphene structures with strong coupling effect; the graphene film is formed by stacking a small number of graphene units up and down; the graphene unit is formed by stacking single-layer graphene sheets in an AB structure mode; and weak coupling is formed between the upper graphene unit and the lower graphene unit.

The prepared graphene film is used for manufacturing a photoelectric device according to the following steps:

(1) firstly, reserving a working window on a Si substrate, plating an insulating layer outside the working window, and then sputtering a Pt electrode layer in the insulating layer;

(2) firstly, laying a graphene film on a working window, contacting with an electrode layer, dripping ethylene glycol at the edge of the graphene film, allowing the ethylene glycol to permeate from the edge of the graphene film to the inside, volatilizing a solvent, and realizing the tight combination of the film and a semiconductor by utilizing the surface tension of the solvent so as to obtain an independent photoelectric device;

(3) and packaging, and connecting with the electrode layer and the semiconductor substrate of the photoelectric device by leads respectively for outputting detection signals.

Applying a reverse bias voltage of-2V to-1V on an electrode and a semiconductor of the device by utilizing a keithley source table for testing; after being connected with the amplifying circuit, the detection circuit is connected with an oscilloscope, and then the detection data can be obtained.

The graphene layer was irradiated with infrared light having a wavelength of 1um and a power of 5mW, and a photocurrent signal of 3.3mA was measured within 20 ns.

A photocurrent signal of 130uA was measured within 18ns by illuminating the graphene layer with infrared light having a wavelength of 4um and a power of 20 mW.

The graphene layer was irradiated with infrared light having a wavelength of 10.6um and a power of 50mW, and a photocurrent signal of 14uA was measured within 20 ns.

Example 9

(1) Removing the substrate of the multilayer graphene prepared by the nickel-based CVD method by using a hydrochloric acid and hydrogen peroxide etching method, and stacking layer by layer until the number of graphene atomic layers is 180.

(2) Annealing for 12h in a graphitization furnace at 2000 ℃.

By Raman testing, it I_D/I_G0.003, the non-AB structure content is 50%; the number of the graphene structural units in the vertical direction is 90, and the number of graphene sheets in a single graphene structural unit is 2.

Testing the vertical stacking structure through TEM electron diffraction, wherein the graphene film comprises a large number of graphene structures with weak coupling effect; the graphene film is formed by stacking a plurality of graphene units up and down; the graphene unit is formed by stacking single-layer graphene sheets in a disordered manner; and weak coupling is formed between the upper graphene unit and the lower graphene unit.

The prepared graphene film is used for manufacturing a photoelectric device according to the following steps:

(1) firstly, reserving a working window on a Si substrate, plating an insulating layer outside the working window, and then sputtering a Pt electrode layer in the insulating layer;

(2) firstly, laying a graphene film on a working window, contacting with an electrode layer, dripping ethylene glycol at the edge of the graphene film, allowing the ethylene glycol to permeate from the edge of the graphene film to the inside, volatilizing a solvent, and realizing the tight combination of the film and a semiconductor by utilizing the surface tension of the solvent so as to obtain an independent photoelectric device;

(3) and packaging, and connecting with the electrode layer and the semiconductor substrate of the photoelectric device by leads respectively for outputting detection signals.

Applying a reverse bias voltage of-2V to-1V on an electrode and a semiconductor of the device by utilizing a keithley source table for testing; after being connected with the amplifying circuit, the detection circuit is connected with an oscilloscope, and then the detection data can be obtained.

Applying a reverse bias voltage of-2V to-1V on an electrode and a semiconductor of the device by utilizing a keithley source table for testing; after being connected with the amplifying circuit, the detection circuit is connected with an oscilloscope, and then the detection data can be obtained.

The graphene layer was irradiated with infrared light having a wavelength of 1um and a power of 5mW, and a photocurrent signal of 5.0mA was measured in 20 ns.

The graphene layer was illuminated with infrared light of wavelength 4um and power 20mW and a photocurrent signal of 190uA was measured in 25 ns.

The graphene layer was irradiated with infrared light having a wavelength of 10.6um and a power of 50mW, and a photocurrent signal of 17uA was measured in 80 ns.

Example 10

(1) Removing the substrate of the multilayer graphene prepared by the nickel-based CVD method by using a hydrochloric acid and hydrogen peroxide etching method, and stacking layer by layer until the number of graphene atomic layers is 180.

(2) Annealing for 2h in a graphitization furnace at 2800 ℃.

By Raman testing, it I_D/I_GIs approximately equal to 0, and the AB structure content is 89 percent; the number of the graphene structural units in the vertical direction is 60, and the number of graphene sheets in a single graphene structural unit is 3.

Testing the vertical stacking structure through TEM electron diffraction, wherein the graphene film comprises a large number of graphene structures with strong coupling effect; the graphene film is formed by stacking a small number of graphene units up and down; the graphene unit is formed by stacking single-layer graphene sheets in an AB structure mode; and weak coupling is formed between the upper graphene unit and the lower graphene unit.

The prepared graphene film is used for manufacturing a photoelectric device according to the following steps:

(1) firstly, reserving a working window on a Si substrate, plating an insulating layer outside the working window, and then sputtering a Pt electrode layer in the insulating layer;

(2) firstly, laying a graphene film on a working window, contacting with an electrode layer, dripping ethylene glycol at the edge of the graphene film, allowing the ethylene glycol to permeate from the edge of the graphene film to the inside, volatilizing a solvent, and realizing the tight combination of the film and a semiconductor by utilizing the surface tension of the solvent so as to obtain an independent photoelectric device;

(3) and packaging, and connecting with the electrode layer and the semiconductor substrate of the photoelectric device by leads respectively for outputting detection signals.

Applying a reverse bias voltage of-2V to-1V on an electrode and a semiconductor of the device by utilizing a keithley source table for testing; after being connected with the amplifying circuit, the detection circuit is connected with an oscilloscope, and then the detection data can be obtained.

The graphene layer was irradiated with infrared light having a wavelength of 1um and a power of 5mW, and a photocurrent signal of 4.1mA was measured within 20 ns.

The graphene layer was illuminated with infrared light of wavelength 4um and power 20mW and a photocurrent signal of 120uA was measured in 25 ns.

The graphene layer was irradiated with infrared light having a wavelength of 10.6um and a power of 50mW, and a photocurrent signal of 11uA was measured within 80 ns.

Example 11

(1) Removing the substrate and the single-layer graphene prepared from the copper-based single-layer graphite by using a hydrochloric acid and hydrogen peroxide etching method for the multilayer graphene prepared by the nickel-based CVD method, and mixing and stacking layer by layer until the number of graphene atomic layers is 180.

(2) Annealing for 2h in a graphitization furnace at 2800 ℃.

By Raman testing, it I_D/I_GIs approximately equal to 0, and the AB structure content is 75 percent; the number of the graphene structural units in the vertical direction is 60, and the number of graphene sheets in a single graphene structural unit is 3.

Testing the vertical stacking structure through TEM electron diffraction, wherein the graphene film comprises a large number of graphene structures with strong coupling effect; the graphene film is formed by stacking a small number of graphene units up and down; the graphene unit is formed by stacking single-layer graphene sheets in an AB structure mode; and weak coupling is formed between the upper graphene unit and the lower graphene unit.

The prepared graphene film is used for manufacturing a photoelectric device according to the following steps:

(1) firstly, reserving a working window on a Si substrate, plating an insulating layer outside the working window, and then sputtering a Pt electrode layer in the insulating layer;

(2) firstly, laying a graphene film on a working window, contacting with an electrode layer, dripping ethylene glycol at the edge of the graphene film, allowing the ethylene glycol to permeate from the edge of the graphene film to the inside, volatilizing a solvent, and realizing the tight combination of the film and a semiconductor by utilizing the surface tension of the solvent so as to obtain an independent photoelectric device;

(3) and packaging, and connecting with the electrode layer and the semiconductor substrate of the photoelectric device by leads respectively for outputting detection signals.

Applying a reverse bias voltage of-2V to-1V on an electrode and a semiconductor of the device by utilizing a keithley source table for testing; after being connected with the amplifying circuit, the detection circuit is connected with an oscilloscope, and then the detection data can be obtained.

The graphene layer was irradiated with infrared light having a wavelength of 1um and a power of 5mW, and a photocurrent signal of 4.4mA was measured within 20 ns.

The graphene layer was irradiated with infrared light having a wavelength of 4um and a power of 20mW, and a photocurrent signal of 130uA was measured in 25 ns.

The graphene layer was irradiated with infrared light having a wavelength of 10.6um and a power of 50mW, and a photocurrent signal of 14uA was measured within 80 ns.

Example 12

(1) And spin-coating a polyimide solution on the multilayer graphene prepared by the nickel-based CVD method to obtain a polyimide/graphene composite film with the total thickness of 100nm, and removing the substrate by using a hydrochloric acid and hydrogen peroxide etching method.

(2) Annealing for 2h in a graphitization furnace at 2800 ℃.

By Raman testing, it I_D/I_GIs approximately equal to 0, and the AB structure content is 90 percent; the number of the graphene structural units in the vertical direction is 14, and the number of graphene sheets in a single graphene structural unit is 9.

Testing the vertical stacking structure through TEM electron diffraction, wherein the graphene film comprises a large number of graphene structures with strong coupling effect; the graphene film is formed by stacking a small number of graphene units up and down; the graphene unit is formed by stacking single-layer graphene sheets in an AB structure mode; and weak coupling is formed between the upper graphene unit and the lower graphene unit.

The prepared graphene film is used for manufacturing a photoelectric device according to the following steps:

(1) firstly, reserving a working window on a Si substrate, plating an insulating layer outside the working window, and then sputtering a Pt electrode layer in the insulating layer;

(2) firstly, laying a graphene film on a working window, contacting with an electrode layer, dripping ethylene glycol at the edge of the graphene film, allowing the ethylene glycol to permeate from the edge of the graphene film to the inside, volatilizing a solvent, and realizing the tight combination of the film and a semiconductor by utilizing the surface tension of the solvent so as to obtain an independent photoelectric device;

(3) and packaging, and connecting with the electrode layer and the semiconductor substrate of the photoelectric device by leads respectively for outputting detection signals.

Applying a reverse bias voltage of-2V to-1V on an electrode and a semiconductor of the device by utilizing a keithley source table for testing; after being connected with the amplifying circuit, the detection circuit is connected with an oscilloscope, and then the detection data can be obtained.

The graphene layer was irradiated with infrared light having a wavelength of 1um and a power of 5mW, and a photocurrent signal of 0.91mA was measured within 20 ns.

The graphene layer was illuminated with infrared light of wavelength 4um and power 20mW and a photocurrent signal of 97uA was measured in 25 ns.

The graphene layer was irradiated with infrared light having a wavelength of 10.6um and a power of 50mW, and a photocurrent signal of 7.3uA was measured in 80 ns.

Example 13

(1) And (3) spin-coating polyacrylonitrile with the thickness of 100nm on the single-layer graphene prepared by the copper-based CVD method, and then removing the substrate by a hydrogen evolution method.

(2) Annealing for 12h in a graphitization furnace at 2300 ℃.

By Raman testing, it I_D/I_G0.04, 50% of non-AB structure content; the number of the graphene structural units in the vertical direction is 60, and the number of graphene sheets in a single graphene structural unit is 2.

Testing the vertical stacking structure through TEM electron diffraction, wherein the graphene film comprises a large number of graphene structures with strong coupling effect; the graphene film is formed by stacking a small number of graphene units up and down; the graphene unit is formed by stacking single-layer graphene sheets in an AB structure mode; and weak coupling is formed between the upper graphene unit and the lower graphene unit.

The prepared graphene film is used for manufacturing a photoelectric device according to the following steps:

(1) firstly, reserving a working window on a Si substrate, plating an insulating layer outside the working window, and then sputtering a Pt electrode layer in the insulating layer;

(2) firstly, laying a graphene film on a working window, contacting with an electrode layer, dripping ethylene glycol at the edge of the graphene film, allowing the ethylene glycol to permeate from the edge of the graphene film to the inside, volatilizing a solvent, and realizing the tight combination of the film and a semiconductor by utilizing the surface tension of the solvent so as to obtain an independent photoelectric device;

(3) and packaging, and connecting with the electrode layer and the semiconductor substrate of the photoelectric device by leads respectively for outputting detection signals.

Applying a reverse bias voltage of-2V to-1V on an electrode and a semiconductor of the device by utilizing a keithley source table for testing; after being connected with the amplifying circuit, the detection circuit is connected with an oscilloscope, and then the detection data can be obtained.

The graphene layer was irradiated with infrared light having a wavelength of 1um and a power of 5mW, and a photocurrent signal of 1.21mA was measured within 20 ns.

The graphene layer was illuminated with infrared light of wavelength 4um and power 20mW and a photocurrent signal of 109uA was measured in 25 ns.

The graphene layer was irradiated with infrared light having a wavelength of 10.6um and a power of 50mW, and a photocurrent signal of 9.2uA was measured in 80 ns.

Example 14

(1) And (3) carrying out suction filtration on the surface of the anodic aluminum oxide by using a suction filtration method to obtain single-layer graphene, then carrying out suction filtration on a mixture of asphalt and graphene oxide with the thickness of 200nm (the mixing mass ratio is 1: 1), and removing the substrate by using a camphor transfer method.

(2) Annealing for 2h in a graphitization furnace at 2800 ℃.

By Raman testing, it I_D/I_GIs approximately equal to 0, and the AB structure content is 95 percent; the number of the graphene structural units in the vertical direction is 8, and the number of graphene sheets in a single graphene structural unit is 19.

Testing the vertical stacking structure through TEM electron diffraction, wherein the graphene film comprises a large number of graphene structures with strong coupling effect; the graphene film is formed by stacking a small number of graphene units up and down; the graphene unit is formed by stacking single-layer graphene sheets in an AB structure mode; and weak coupling is formed between the upper graphene unit and the lower graphene unit.

The prepared graphene film is used for manufacturing a photoelectric device according to the following steps:

(1) firstly, reserving a working window on a Si substrate, plating an insulating layer outside the working window, and then sputtering a Pt electrode layer in the insulating layer;

(2) firstly, laying a graphene film on a working window, contacting with an electrode layer, dripping ethylene glycol at the edge of the graphene film, allowing the ethylene glycol to permeate from the edge of the graphene film to the inside, volatilizing a solvent, and realizing the tight combination of the film and a semiconductor by utilizing the surface tension of the solvent so as to obtain an independent photoelectric device;

(3) and packaging, and connecting with the electrode layer and the semiconductor substrate of the photoelectric device by leads respectively for outputting detection signals.

Applying a reverse bias voltage of-2V to-1V on an electrode and a semiconductor of the device by utilizing a keithley source table for testing; after being connected with the amplifying circuit, the detection circuit is connected with an oscilloscope, and then the detection data can be obtained.

The graphene layer was irradiated with infrared light having a wavelength of 1um and a power of 5mW, and a photocurrent signal of 3.1mA was measured within 20 ns.

The graphene layer was illuminated with infrared light of wavelength 4um and power 20mW and a photocurrent signal of 112uA was measured in 25 ns.

The graphene layer was irradiated with infrared light having a wavelength of 10.6um and a power of 50mW, and a photocurrent signal of 12.5uA was measured in 80 ns.