阅读说明：本技术 含锡的多元化合物光吸收层以及光电器件的制备方法 (Tin-containing multi-component compound light absorption layer and preparation method of photoelectric device ) 是由 杨佳伟 冯叶 杨春雷 张陈斌 张玉萍 彭燕君 张琛 王伟 于 2021-08-19 设计创作，主要内容包括：本发明提供了一种含锡的多元化合物光吸收层的制备方法,其包括：制备获得含锡的多元化合物光吸收层的前驱体材料层；使用脉冲激光对所述前驱体材料层进行激光热退火处理以使所述前驱体材料层发生重结晶,制备获得所述含锡的多元化合物光吸收层。本发明还公开了一种光电器件的制备方法,其中,所述光电器件中的光吸收层采用如上所述的含锡的多元化合物光吸收层的制备方法制备形成。本发明的技术方案,在含锡的多元化合物光吸收层的制备工艺中,引入了脉冲激光热处理工艺,利用脉冲激光热处理提高样品薄膜的瞬态温度,减少化合物薄膜材料在高温退火过程中的组分流失,特别是锡的流失,由此提高制备获得的光吸收层的品质。(The invention provides a preparation method of a tin-containing multi-component compound light absorption layer, which comprises the following steps: preparing a precursor material layer for obtaining the tin-containing multi-component compound light absorption layer; and carrying out laser thermal annealing treatment on the precursor material layer by using pulse laser so as to recrystallize the precursor material layer, and preparing the tin-containing multi-component compound light absorption layer. The invention also discloses a preparation method of the photoelectric device, wherein the light absorption layer in the photoelectric device is prepared and formed by adopting the preparation method of the tin-containing multi-component compound light absorption layer. According to the technical scheme, a pulse laser heat treatment process is introduced into the preparation process of the tin-containing multi-component compound light absorption layer, the transient temperature of the sample film is improved by utilizing the pulse laser heat treatment, and the component loss, particularly the tin loss, of the compound film material in the high-temperature annealing process is reduced, so that the quality of the prepared light absorption layer is improved.)

1. A method for preparing a tin-containing multi-component compound light absorption layer is characterized by comprising the following steps:

preparing a precursor material layer for obtaining the tin-containing multi-component compound light absorption layer;

and carrying out laser thermal annealing treatment on the precursor material layer by using pulse laser so as to recrystallize the precursor material layer, and preparing the tin-containing multi-component compound light absorption layer.

2. The method according to claim 1, wherein the laser thermal annealing treatment of the precursor material layer using a pulsed laser comprises: placing the precursor material layer in a thermal treatment device, and providing the pulse laser to scan the surface of the precursor material layer; wherein the frequency of the pulse laser is 100 Hz-10000 Hz, the power is 9W-30W, the laser wavelength is 635 nm-1064 nm, the scanning interval is 0.03 mm-0.07 mm, and the scanning speed is 10 mm/s-200 mm/s.

3. The method according to claim 2, wherein the pulsed laser is used to cyclically scan the precursor material layer for 2 or more times.

4. The method according to claim 3, wherein the pulsed laser is used to cyclically scan the precursor material layer for 2 to 10 times.

5. The method according to claim 2, wherein the precursor material layer is placed in a heat treatment apparatus, a mixed gas of a first gas and a second gas is introduced into the heat treatment apparatus, the precursor material layer is heated to a predetermined temperature, and then the surface of the precursor material layer is scanned with the pulsed laser under the predetermined temperature condition; wherein the first gas is H₂Se or H₂And S gas, wherein the second gas is nitrogen or argon.

6. The method according to claim 5, wherein the first gas is H in the mixed gas₂Se, then H in the mixed gas₂The volume percentage of Se is 2-3 percent; if the first gas is H₂S, then H in the mixed gas₂The volume percentage of S is 1-6%; the predetermined temperature is 300-400 ℃.

7. The method for producing a tin-containing multi-component light-absorbing layer as claimed in any one of claims 1 to 6, wherein the tin-containing multi-component compound is a multi-component compound containing copper, zinc, tin, sulfur and selenium or a multi-component compound containing copper, cadmium, zinc, tin and selenium.

8. The method of claim 7, wherein the precursor material layer for obtaining the tin-containing multi-component light absorption layer is prepared by co-evaporation in a vacuum evaporation apparatus.

9. A method for manufacturing an optoelectronic device, wherein a light absorption layer in the optoelectronic device is formed by the method for manufacturing a tin-containing multi-component compound light absorption layer according to any one of claims 1 to 8.

10. The method for manufacturing an optoelectronic device according to claim 9, wherein the optoelectronic device is a thin film solar cell, and the method for manufacturing the thin film solar cell comprises:

s10, providing a support substrate, and preparing and forming a bottom electrode layer on the support substrate;

s20, preparing and forming a light absorption layer on the bottom electrode layer by the method for preparing the tin-containing multi-component compound light absorption layer according to any one of claims 1 to 8;

s30, preparing and forming a cadmium sulfide buffer layer on the light absorption layer;

s40, preparing and forming a window layer on the cadmium sulfide buffer layer;

and S50, preparing and forming a top electrode layer on the window layer to obtain the thin film solar cell.

Technical Field

The invention belongs to the technical field of photoelectric devices, and particularly relates to a preparation method of a tin-containing multi-component compound light absorption layer and a preparation method of a photoelectric device.

Background

Solar cell technology is a clean and renewable energy technology, and has been in the way of a great deal of fields through decades of development. The conversion efficiency of the traditional silicon-based solar cell almost reaches the bottleneck, and the development of light weight and flexibility is limited by the indirect band gap characteristic, so that the thin-film solar cell enters the field of the industry at present. The thin-film solar cell has the advantages of high productivity, high photoelectric conversion efficiency, good stability, short energy recovery period and the like, and high-performance devices can be prepared on some flexible substrates.

The CZTSSe thin film solar cell taking the copper zinc tin sulfur selenium (CZTSSe) thin film as the light absorption layer has the theoretical photoelectric conversion efficiency of 31 percent, has huge potential, and has the advantages of low cost, good stability, high efficiency and the like. In order to produce a thin-film solar cell having high photoelectric conversion efficiency, post-annealing the light-absorbing layer is a commonly used treatment method. The annealing process is a process for promoting the formation of a crystalline phase of a light absorption layer of the solar cell, the crystal growth and the stress release, and after the annealing temperature reaches a certain high temperature level, the higher the temperature is, the better the crystallization effect is, and the fewer defect states in the light absorption layer are, so that the carrier recombination can be effectively inhibited, and the photoelectric conversion efficiency of the device is improved. As a multi-component material, CZTSSe can be influenced by various factors in the growth and crystallization process, and in a high-temperature annealing stage, the inside of a CZTSSe light absorption layer is often accompanied by component loss, particularly the content of tin is reduced. At high temperature, the CZTSSe compound film is decomposed into binary sulfide or selenide of copper, zinc, tin, etc., wherein the volatile tin sulfide (selenide) is gradually lost during heating, and the heat treatment process is usually performed in a low pressure atmosphere below atmospheric pressure, which further increases the loss of tin. The electronic structure of the surface of the CZTSSe thin film without tin element is not beneficial to the formation of a P/N junction, so that the efficiency of the device is greatly reduced.

Aiming at the problem of tin loss in the rapid heat treatment process of the CZTSSe light absorption layer, the currently adopted method is to add tin sulfide (selenide) to provide the steam partial pressure of tin, promote the chemical equilibrium of the CZTSSe decomposition reaction to move to the left and reduce the volatilization of the tin sulfide (selenide). The CZTSSe decomposition reaction is as follows:

(1)、

(2)、

at present, a method for reducing the loss of tin in the CZTSSe light absorption layer by adding tin sulfide (selenide) at a high temperature to form tin partial pressure in the rapid thermal treatment process has achieved certain success. However, since the formation of tin partial pressure is subject to a solid powder-to-gas transition process, it is difficult to precisely control the entire process in a rapid thermal processing apparatus. The rate of conversion of the powder into gas, the degree of condensation on the walls of the apparatus, the partial pressure actually formed, etc., are difficult to analyze qualitatively, and from these points the process is not controllable. To date, no complete theoretical system has been formed about the crystallization mechanism of the CZTSSe light absorbing layer during annealing, and in order to further explore and optimize the current processes and methods, it is necessary to reduce the influence of these uncontrollable factors on the existing systems.

Disclosure of Invention

In view of the defects in the prior art, the invention provides a preparation method of a tin-containing multi-component compound light absorption layer, which aims to solve the problem of tin loss in the rapid heat treatment process of the tin-containing multi-component compound light absorption layer.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method for preparing a tin-containing multi-component compound light absorption layer, comprising:

preparing a precursor material layer for obtaining the tin-containing multi-component compound light absorption layer;

and carrying out laser thermal annealing treatment on the precursor material layer by using pulse laser so as to recrystallize the precursor material layer, and preparing the tin-containing multi-component compound light absorption layer.

Specifically, the laser thermal annealing treatment of the precursor material layer by using the pulsed laser comprises the following steps: placing the precursor material layer in a thermal treatment device, and providing the pulse laser to scan the surface of the precursor material layer; wherein the frequency of the pulse laser is 100 Hz-10000 Hz, the power is 9W-30W, the laser wavelength is 635 nm-1064 nm, the scanning interval is 0.03 mm-0.07 mm, and the scanning speed is 10 mm/s-200 mm/s.

Specifically, the precursor material layer is cyclically scanned 2 times or more using the pulsed laser.

Specifically, the pulsed laser is used to cyclically scan the precursor material layer 2-10 times.

Specifically, the precursor material layer is placed in a heat treatment device, mixed gas of first gas and second gas is introduced into the heat treatment device, the precursor material layer is heated to a preset temperature, and then the precursor material layer is preheatedScanning the surface of the precursor material layer by using the pulse laser under a constant temperature condition; wherein the first gas is H₂Se or H₂And S gas, wherein the second gas is nitrogen or argon.

Specifically, in the mixed gas, if the first gas is H₂Se, then H in the mixed gas₂The volume percentage of Se is 2-3 percent; if the first gas is H₂S, then H in the mixed gas₂The volume percentage of S is 1-6%; the predetermined temperature is 300-400 ℃.

Specifically, the tin-containing multi-component compound is a multi-component compound containing copper, zinc, tin, sulfur and selenium or a multi-component compound containing copper, cadmium, zinc, tin and selenium.

Specifically, a co-evaporation method is adopted in a vacuum evaporation device to prepare a precursor material layer of the tin-containing multi-component compound light absorption layer.

Another aspect of the present invention is to provide a method for manufacturing an optoelectronic device, wherein a light absorbing layer in the optoelectronic device is formed by using the method for manufacturing a tin-containing multi-component compound light absorbing layer as described above.

Specifically, the photoelectric device is a thin film solar cell, and the preparation method of the thin film solar cell comprises the following steps:

s10, providing a support substrate, and preparing and forming a bottom electrode layer on the support substrate;

s20, preparing and forming a light absorption layer on the bottom electrode layer by adopting the preparation method of the tin-containing multi-component compound light absorption layer;

s30, preparing and forming a cadmium sulfide buffer layer on the light absorption layer;

s40, preparing and forming a window layer on the cadmium sulfide buffer layer;

and S50, preparing and forming a top electrode layer on the window layer to obtain the thin film solar cell.

According to the preparation method of the tin-containing multi-component compound light absorption layer provided by the embodiment of the invention, in the preparation process of the tin-containing multi-component compound light absorption layer, a pulse laser heat treatment process is introduced, the transient temperature of a sample film is improved by utilizing the pulse laser heat treatment, and the component loss, particularly the loss of tin, of a compound film material in the high-temperature annealing process is reduced, so that the quality of the prepared light absorption layer is improved.

Drawings

Fig. 1 is a flowchart of a method for producing a tin-containing multi-component compound light-absorbing layer in an embodiment of the present invention;

FIG. 2 is an exemplary illustration of a laser thermal annealing process using a pulsed laser in an embodiment of the present invention;

fig. 3 is a schematic structural view of a thin film solar cell fabricated in an embodiment of the present invention;

FIG. 4 is an SEM image of a CZTS thin film prepared in an example of the present invention;

FIG. 5 is an SEM image of a CZTS thin film obtained by comparative example preparation in an example of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention are described in detail below with reference to the accompanying drawings. Examples of these preferred embodiments are illustrated in the accompanying drawings. The embodiments of the invention shown in the drawings and described in accordance with the drawings are exemplary only, and the invention is not limited to these embodiments.

It should be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and/or processing steps closely related to the scheme according to the present invention are shown in the drawings, and other details not so relevant to the present invention are omitted.

Embodiments of the present invention first provide a method for preparing a tin-containing multi-component compound light absorption layer, for example, a multi-component compound containing copper, zinc, tin, sulfur, and selenium (CZTSSe), or a multi-component compound containing copper, cadmium, zinc, tin, and selenium (CCZTSe), for example.

Referring to fig. 1, the method for preparing the tin-containing multi-component compound light absorption layer includes the following steps:

and S1, preparing a precursor material layer of the tin-containing multi-component compound light absorption layer.

Specifically, the precursor material layer is preferably prepared by: and providing a support substrate, placing the support substrate in a vacuum evaporation device, and preparing a precursor material layer of the tin-containing multi-component compound light absorption layer on the support substrate in the vacuum evaporation device by adopting a co-evaporation method.

And S2, carrying out laser thermal annealing treatment on the precursor material layer by using pulse laser to recrystallize the precursor material layer, and preparing the tin-containing multi-component compound light absorption layer.

Specifically, step S2 includes: and placing the precursor material layer in a thermal treatment device, and providing the pulsed laser to scan the surface of the precursor material layer. Referring to fig. 2, as shown in fig. 2, a precursor material layer 1 of a tin-containing multi-component compound light absorption layer is formed on a support substrate 2, and a pulsed laser 3 is provided to scan the surface of the precursor material layer 1.

In some preferred embodiments, the pulsed laser has a frequency of 100Hz to 10000Hz, such as 100Hz, 200Hz, 500Hz, 1000Hz, 2000Hz, 5000Hz, 8000Hz or 10000Hz, a power of 9W to 30W, such as 9W, 12W, 15W, 20W, 25W, 27W or 30W, a laser wavelength of 635nm to 1064nm, such as 635nm, 670nm, 946nm, 1053nm or 1064nm, a scanning interval of 0.03mm to 0.07mm, such as 0.03mm, 0.04mm, 0.05mm, 0.06mm or 0.07mm, and a scanning speed of 10mm/s to 200mm/s, such as 10mm/s, 50mm/s, 80mm/s, 100mm/s, 120mm/s, 160mm/s, 180mm/s or 200 mm/s.

In some preferable schemes, the pulsed laser is used to perform more than 2 times of cyclic scanning on the precursor material layer. More preferably, the pulsed laser is used to cyclically scan the precursor material layer 2-10 times.

In some preferable schemes, the precursor material layer is placed in a heat treatment device, and a mixed gas of a first gas and a second gas is introduced into the heat treatment deviceHeating the precursor material layer to a preset temperature, and then scanning the surface of the precursor material layer by using the pulse laser under the preset temperature condition; wherein the first gas is H₂Se or H₂And S gas, wherein the second gas is nitrogen or argon.

Wherein, in the mixed gas, if the first gas is H₂Se, then H in the mixed gas₂The volume percentage of Se is 2-3 percent; if the first gas is H₂S, then H in the mixed gas₂The volume percentage of S is 1-6%. The preset temperature is 300-400 ℃, firstly, the precursor material layer is heated to 300-400 ℃ within 15-30 min, then the temperature is kept for 20-40 min, and then laser processing equipment is started at the temperature of 300-400 ℃ to perform scanning annealing treatment on the surface of the precursor material layer.

The embodiment of the invention also provides a preparation method of the photoelectric device, wherein the light absorption layer in the photoelectric device is prepared and formed by adopting the preparation method of the tin-containing multi-component compound light absorption layer.

As mentioned above, the tin-containing multi-component compound is, for example, a multi-component compound (CZTSSe) containing copper, zinc, tin, sulfur and selenium, in which case the optoelectronic device is, for example, a thin film solar cell containing a CZTSSe light absorbing layer; the tin-containing multi-component compound is, for example, a multi-component compound containing copper, cadmium, zinc, tin and selenium (CCZTSe), in which case the optoelectronic device is, for example, an infrared detector containing a CCZTSe light-absorbing layer.

In this embodiment, the photovoltaic device is a thin film solar cell, and the tin-containing multi-component compound light absorption layer is a CZTSSe light absorption layer. Referring to fig. 3, the method for manufacturing the thin film solar cell includes:

and S10, providing the supporting substrate 10, and preparing and forming the bottom electrode layer 20 on the supporting substrate.

Specifically, a cleaned soda-lime glass substrate is placed in a radio frequency magnetron sputtering molybdenum chamber, argon is introduced to control the air pressure in the chamber to be 2.0Pa, direct current sputtering is carried out for 8 circles with 350W power, sputtering is carried out for 4 circles with 1000W power under the air pressure of 0.3Pa, Ar gas is closed, and the sample is taken out after cooling for 5-10 min. A Mo electrode with a thickness of about 500nm was obtained as the bottom electrode layer 20.

And S20, preparing and forming the light absorption layer 30 on the bottom electrode layer 20. Specifically, the light absorbing layer 30 is formed on the bottom electrode layer 20 by using the method for manufacturing a tin-containing multi-component light absorbing layer according to the foregoing embodiment of the present invention.

Specifically, the sample with the prepared molybdenum electrode is sent into an MBE vacuum coating cavity, and the vacuum degree is controlled to be 2 multiplied by 10^-5Pa, the equipment adopts a four-source simultaneous evaporation method, uses Cu, Zn, Sn and Se as source materials, and prepares a precursor with proper element proportion in one step, such as: copper/(zinc + tin) is approximately equal to 0.8, and zinc/tin is approximately equal to 1.1.

In this embodiment, first, the substrate and the source furnace are heated, the substrate is heated to 150 ℃, the source furnace is heated to the working temperature (for example, Cu 1187 ℃, Zn 393 ℃, Sn 1183 ℃, Se 270 ℃) and is kept for 15min, then the baffle is opened, meanwhile, evaporation is performed for about 30min, after the evaporation is finished, the baffle is closed, and the substrate is taken out after being cooled to below 100 ℃, so as to obtain a CZTSe material layer with a thickness of about 2 μm.

Then, the CZTSe material layer sample is placed in a heat treatment device, and 0.4kPa H is firstly introduced₂S and 19.6kPa N₂Separately controlling H by valve control₂S gas and N₂The flow rate of the gas is 0.5sccm and 24.5 sccm; and raising the temperature of the CZTSe material layer sample in the heat treatment equipment to 350 ℃ within 15min, and keeping the temperature for 30 min. In the above process, part of Se element in the CZTSe material layer is replaced by S element, forming a CZTSSe material layer sample.

Then, under the condition that the temperature of the sample is kept at 350 ℃, laser heat treatment equipment is started, the laser wavelength is 1064nm, the sample is heated, the laser repetition frequency is 1000Hz, the laser power is 70% (total power is 30w), the scanning interval is 0.05mm, the scanning speed is 100mm/s, the cyclic scanning is carried out for 3 times, and finally, the sample is naturally cooled to prepare the CZTSSe light absorption layer 30.

An SEM image of the CZTSSe light absorbing layer 30 obtained by the present example using the pulsed laser for thermal annealing is shown in fig. 4. In comparison, the example of the present invention also performed the treatment using the conventional high temperature thermal annealing process, the annealing temperature of the high temperature thermal annealing process was 510 ℃, the annealing time was 15min, and the SEM image of the CZTSSe light absorbing layer obtained in the comparative example is shown in fig. 5. Comparing fig. 4 and fig. 5, it can be seen that the CZTSSe light absorbing layer prepared by using laser heat treatment in the embodiment of the present invention has a flatter surface and a more uniform size of crystal grains while ensuring large crystal grains, which indicates that the laser heat treatment method can reduce the loss of components and ensure the absorption layer to be crystallized with higher quality, and the laser heat treatment process is performed at a lower temperature.

S30, forming a cadmium sulfide buffer layer 40 on the light absorbing layer 30.

Specifically, 5.694g of thiourea is weighed and dissolved in 150mL of deionized water, 0.184g of cadmium sulfate is weighed and dissolved in 60mL of deionized water, 45mL of ammonia water with the concentration of 30% is added, 425mL of deionized water is weighed and poured into a reactor, the mixed solution of the thiourea aqueous solution, the cadmium sulfate and the ammonia water is introduced into the reactor, the heat-treated sample is placed in the center of the reactor, the reactor is placed into a water bath kettle with the constant temperature of 67 ℃, a stirrer is opened, and the CdS buffer layer material is uniformly grown by a chemical water bath method. After 9min of reaction, the instrument was closed, the sample was taken out, the sample was rapidly rinsed with deionized water, and N was used₂Drying, and annealing in an oven at 160 ℃ for 2min to obtain the cadmium sulfide buffer layer 40.

S40, preparing and forming a window layer 50 on the cadmium sulfide buffer layer 40.

Specifically, the window layer 50 includes an Intrinsic Zinc Oxide (IZO) layer 51 and an aluminum-doped zinc oxide (AZO) layer 52. The Intrinsic Zinc Oxide (IZO) window layer is subjected to low-power 120W sputtering and then high-power 500W sputtering, and a loose layer is formed through the low-power sputtering, so that the Intrinsic Zinc Oxide (IZO) window layer can be better combined with the CdS buffer layer and is not easy to fall off. An aluminum doped zinc oxide (AZO) layer was sputtered at 750W at 500W to an AZO target. The total thickness of the window layer was 250 nm.

And S50, preparing and forming a top electrode layer 60 on the window layer 50 to obtain the thin film solar cell.

In this embodiment, the top electrode layer 60 includes a first nickel metal layer, an aluminum metal layer, and a second nickel metal layer stacked together.

In summary, in the preparation method of the tin-containing multi-component compound light absorption layer provided by the embodiment of the invention, the pulse laser heat treatment process is introduced in the preparation process of the tin-containing multi-component compound light absorption layer, the transient temperature of the sample thin film is increased by using the pulse laser heat treatment, and the component loss, especially the tin loss, of the compound thin film material in the high-temperature annealing process is reduced, so that the quality of the prepared light absorption layer is improved.

The foregoing is directed to embodiments of the present application and it is noted that numerous modifications and adaptations may be made by those skilled in the art without departing from the principles of the present application and are intended to be within the scope of the present application.