阅读说明：本技术 一种基于硒化亚锡/硒化铟异质结的光电探测器及其制备方法 (Photoelectric detector based on stannous selenide/indium selenide heterojunction and preparation method thereof ) 是由 李煜 晏雨发 张晗 李峰 于 2020-07-22 设计创作，主要内容包括：本发明涉及一种基于硒化亚锡/硒化铟异质结的光电探测器及其制备方法,其中,所述基于硒化亚锡/硒化铟异质结的光电探测器包括设置在衬底上的p型硒化亚锡薄膜和n型硒化铟薄膜,所述p型硒化亚锡薄膜和n型硒化铟薄膜之间设置有部分重叠区域,所述部分重叠区域通过范德华相互作用形成光电异质结,所述p型硒化亚锡薄膜和n型硒化铟薄膜不重叠的两端分别固定有一金属电极。本发明通过构建pn异质结,使p型硒化亚锡薄膜与n型硒化铟薄膜在光照条件下产生的电子与空穴在异质结处迅速分离,能够有效降低暗电流,明显提高所制备的光电探测器的光增益、光响应速度及光响应度。(The invention relates to a photoelectric detector based on a stannous selenide/indium selenide heterojunction and a preparation method thereof, wherein the photoelectric detector based on the stannous selenide/indium selenide heterojunction comprises a p-type stannous selenide thin film and an n-type indium selenide thin film which are arranged on a substrate, a partial overlapping area is arranged between the p-type stannous selenide thin film and the n-type indium selenide thin film, the partial overlapping area forms the photoelectric heterojunction through van der Waals interaction, and two non-overlapping ends of the p-type stannous selenide thin film and the n-type indium selenide thin film are respectively fixed with a metal electrode. According to the invention, through constructing the pn heterojunction, electrons and holes generated by the p-type stannous selenide film and the n-type indium selenide film under the illumination condition are rapidly separated at the heterojunction, so that the dark current can be effectively reduced, and the optical gain, the optical response speed and the optical response degree of the prepared photoelectric detector are obviously improved.)

1. The utility model provides a photoelectric detector based on stannous selenide/indium selenide heterojunction which characterized in that, is including setting up p type stannous selenide film and the n type indium selenide film on the substrate, be provided with the partial overlap area between p type stannous selenide film and the n type indium selenide film, the partial overlap area forms the photoelectric heterojunction through van der Waals interact, the non-overlapping both ends of p type stannous selenide film and n type indium selenide film are fixed with a metal electrode respectively.

2. A stannous selenide/indium selenide heterojunction-based photodetector according to claim 1, wherein the p-type stannous selenide thin film has a thickness of 0.5nm to 50 nm.

3. A stannous selenide/indium selenide heterojunction-based photodetector according to claim 1, wherein the thickness of the n-type indium selenide thin film is 0.8nm to 80 nm.

4. A stannous selenide/indium selenide heterojunction-based photodetector according to claim 1, wherein the substrate comprises a silicon substrate and an insulating substrate disposed on the silicon substrate.

5. A stannous selenide/indium selenide heterojunction-based photodetector according to claim 1, wherein the material of the insulating substrate is silicon dioxide.

6. A stannous selenide/indium selenide heterojunction-based photodetector according to claim 1, wherein the material of the metal electrode is one of gold, titanium, chromium, nickel and tungsten.

7. A preparation method of a photoelectric detector based on a stannous selenide/indium selenide heterojunction is characterized by comprising the following steps:

cleaning the substrate by using acetone, ethanol and deionized water;

preparing a p-type stannous selenide film and an n-type indium selenide film in advance;

transferring the p-type stannous selenide film to the surface of a substrate, and then directionally transferring the n-type indium selenide film to the position above the p-type stannous selenide film through a micromechanical transfer platform and partially overlapping the p-type stannous selenide film;

and manufacturing an electrode pattern on the substrate, and preparing a metal electrode in an evaporation mode to obtain the photoelectric detector based on the stannous selenide/indium selenide heterojunction.

8. The method for preparing a photoelectric detector based on a stannous selenide/indium selenide heterojunction as claimed in claim 7, wherein the p-type stannous selenide film is prepared by a physical vapor deposition method.

9. The method for preparing a photoelectric detector based on a stannous selenide/indium selenide heterojunction as claimed in claim 7, wherein the n-type indium selenide thin film is prepared by a mechanical stripping method.

10. The method of claim 7, wherein the step of transferring the p-type stannous selenide thin film to the surface of the substrate comprises:

and transferring the p-type stannous selenide film onto a PDMS substrate, and transferring the p-type stannous selenide film from the PDMS substrate to the surface of the substrate through a micromechanical transfer platform.

Technical Field

The invention relates to the field of photoelectric detection, in particular to a photoelectric detector based on a stannous selenide/indium selenide heterojunction and a preparation method thereof.

Background

The principle of the photoelectric detector is that the conductivity of an irradiated material is changed through radiation, wherein the semiconductor photoelectric detector mainly changes the electrical property through the fact that photons excite unbalanced carriers in a semiconductor material, and has the characteristics of small volume, integration, high response speed, high sensitivity and the like. According to different detectable light bands, the optical detector can be divided into an ultraviolet light detector, a visible light detector and an infrared light detector, wherein the ultraviolet light detector is mainly used for communication, missile early warning and tracking, astronomy, disaster weather forecast, fire early warning, marine oil pollution monitoring, biomedicine and the like, the visible near infrared light detector is mainly used for imaging technology, ray measurement and detection, an industrial automatic control system, optical metering and the like, and the infrared light detector is mainly used for forest fire monitoring, smoke alarms, night vision equipment, infrared remote sensing and the like.

Stannous selenide (SnSe) is a chemically stable group IV-VI semiconductor compound with abundant content, and belongs to C_2vThe space point group is stable even if the space point group is thinned to a single layer. The stannous selenide is similar to black phosphorus in structure and is a layered material, an upper layer and a lower layer of atoms form in the layer, each atom and three surrounding atoms form strong Sn-Se covalent bonds, but the bonding force between the layers is very weak, the two-dimensional material is easy to prepare by stripping, and the stannous selenide has strong anisotropy in the Armchair direction and the Zigzag direction. The natural stannous selenide is a p-type semiconductor, the indirect band gap of the stannous selenide is 0.90eV, the direct band gap of the stannous selenide is 1.30eV, and the stannous selenide can be used in a photoelectric detector, but the current-carrying concentration of the stannous selenide is higher, the photoelectric detector based on the stannous selenide alone has larger dark current and smaller photocurrent gain, so that the photoresponse time and the photoresponse degree of the photoelectric detector are obviously influenced.

Accordingly, the prior art remains to be improved and developed.

Disclosure of Invention

In view of the defects of the prior art, the present application aims to provide a photodetector based on a stannous selenide/indium selenide heterojunction and a preparation method thereof, and aims to solve the technical problems of long optical response time and low optical response of the existing stannous selenide photodetector.

The technical scheme of the invention is as follows:

the utility model provides a photoelectric detector based on stannous selenide/indium selenide heterojunction, wherein, including setting up p type stannous selenide film and the n type indium selenide film on the substrate, be provided with the partial overlap area between p type stannous selenide film and the n type indium selenide film, the partial overlap area forms the photoelectric heterojunction through van der Waals interact, the non-overlapping both ends of p type stannous selenide film and n type indium selenide film are fixed with a metal electrode respectively.

In the implementation mode, a plurality of electrons and holes can be generated inside the p-type stannous selenide film and the n-type indium selenide film through illumination, and photo-generated electron holes can be rapidly separated at the heterojunction, so that dark current can be effectively reduced, and the optical gain, the optical response speed and the optical responsivity of the prepared photoelectric detector are improved.

Optionally, the thickness of the p-type stannous selenide thin film is 0.5nm-50 nm.

Optionally, the thickness of the n-type indium selenide thin film is 0.8nm-80 nm.

Optionally, the substrate includes a silicon substrate and an insulating substrate disposed on the silicon substrate.

Optionally, the material of the insulating substrate is silicon dioxide.

Optionally, the material of the metal electrode is one of gold, titanium, chromium, nickel and tungsten.

Based on the same inventive concept, the invention also provides a preparation method of the stannous selenide/indium selenide heterojunction photoelectric detector, wherein the preparation method comprises the following steps:

cleaning the substrate by using acetone, ethanol and deionized water;

preparing a p-type stannous selenide film and an n-type indium selenide film in advance;

transferring the p-type stannous selenide film to the surface of a substrate, and then directionally transferring the n-type indium selenide film to the position above the p-type stannous selenide film through a micromechanical transfer platform and partially overlapping the p-type stannous selenide film;

and manufacturing an electrode pattern on the substrate, and preparing a metal electrode in an evaporation mode to obtain the photoelectric detector based on the stannous selenide/indium selenide heterojunction.

Optionally, the p-type stannous selenide film is prepared by a physical vapor deposition method.

Optionally, the n-type indium selenide thin film is prepared by a mechanical stripping method.

Optionally, the step of transferring the p-type stannous selenide thin film to the surface of the substrate comprises:

and transferring the p-type stannous selenide film onto a PDMS substrate, and transferring the p-type stannous selenide film from the PDMS substrate to the surface of the substrate through a micromechanical transfer platform.

Drawings

Fig. 1 is a schematic structural diagram of a preferred embodiment of the photodetector based on a stannous selenide/indium selenide heterojunction prepared by the present invention.

Fig. 2 is a schematic structural diagram of another preferred embodiment of the photodetector based on the stannous selenide/indium selenide heterojunction prepared by the present invention.

Fig. 3 is an I-V curve diagram of the detection of different wavelengths of light by the photoelectric detector based on the stannous selenide/indium selenide heterojunction prepared in the embodiment 1 of the present invention.

Fig. 4 is a graph of the optical response time of the photodetector based on the stannous selenide/indium selenide heterojunction prepared in example 1 of the present invention.

Detailed Description

To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present application are given in the accompanying drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

The invention provides a photoelectric detector based on a stannous selenide/indium selenide heterojunction, and aims to solve the technical problems that the photoelectric detector based on the existing stannous selenide has long light response time and low light response, as shown in fig. 1, the photoelectric detector based on the stannous selenide/indium selenide heterojunction comprises a p-type stannous selenide film 2 and an n-type indium selenide film 3 which are arranged on a substrate 1, a partial overlapping area is arranged between the p-type stannous selenide film 2 and the n-type indium selenide film 3, the partial overlapping area forms the photoelectric heterojunction through van der waals interaction, and two non-overlapping ends of the p-type stannous selenide film 2 and the n-type indium selenide film 3 are respectively fixed with a metal electrode 4.

In this embodiment, the stannous selenide is a natural p-Type semiconductor material, the band gap of the stannous selenide is 0.9eV, the detection band is wider, but the carrier concentration of the stannous selenide is higher, so that the dark current of the stannous selenide is larger, indium selenide is an n-Type semiconductor material, the band gap of the indium selenide is 1.3eV, the detection band is narrower than the stannous selenide, but the dark current of the indium selenide is smaller, when the p-Type stannous selenide film and the n-Type indium selenide film are overlapped to form a heterojunction, because the positions of the conduction band and the valence band of the two materials are different, the conduction band of the indium selenide is located between the conduction band and the valence band of the stannous selenide, and a Type-ii energy band heterostructure is formed.

Further, since the fermi level of the indium selenide is different from that of the stannous selenide, when a heterojunction is formed, in a heterojunction region, holes in the p-type stannous selenide film tend to move to the n-type indium selenide film side, and electrons in the n-type indium selenide film move to the p-type stannous selenide film, so that an energy band of a surface of the n-type indium selenide film, which is in contact with the p-type stannous selenide film, is bent upward, an energy band of a surface of the p-type stannous selenide film, which is in contact with the n-type indium selenide film, is bent downward, so that the fermi levels of the p-type stannous selenide film and the n-type indium selenide film are at the same level, and meanwhile, an internal electric field is formed near an interface between the p-type stannous selenide film and the n-type indium selenide film, and the formation of the internal electric field can ensure that the formed heterojunction works under a zero external bias condition, under the illumination condition, a large number of electrons and holes can be generated in the p-type stannous selenide film and the n-type indium selenide film, and the electrons and the holes can be rapidly separated under the action of an internal electric field, so that photocurrent is generated, and the detection of light rays is realized.

In the embodiment, by constructing the pn heterojunction, electrons and holes generated by the p-type stannous selenide film and the n-type indium selenide film under the illumination condition are rapidly separated at the heterojunction, so that the dark current can be effectively reduced, and the optical gain, the optical response speed and the optical response degree of the prepared photoelectric detector are obviously improved.

In some embodiments, the p-type stannous selenide thin film has a thickness from 0.5nm to 50 nm. In this embodiment, the thickness of the p-type stannous selenide film is 0.5nm to 50nm, and the number of corresponding layers is 1 to 100.

In some embodiments, the thin film of n-type indium selenide has a thickness from 0.8nm to 80 nm. In this embodiment, the thickness of the n-type indium selenide thin film is 0.8nm to 80nm, and the number of corresponding layers is 1 to 100.

In some implementations, the substrate includes a silicon substrate and an insulating substrate disposed on the silicon substrate. In this embodiment, as shown in fig. 2, the substrate 1 includes a silicon substrate 10 and an insulating substrate 11 disposed on the silicon substrate 10, and since the silicon substrate 10 is a highly doped material and has strong conductivity, a layer of insulating substrate 11 is disposed on the silicon substrate 10 in this embodiment, and preferably, the material of the insulating substrate 11 is silicon dioxide.

In some embodiments, the material of the metal electrode is one of gold, titanium, chromium, nickel, and tungsten. In this embodiment, a metal electrode is fixed at each of the non-overlapping ends of the p-type stannous selenide film and the n-type indium selenide film, the metal electrode is made of one of gold, titanium, chromium, nickel and tungsten, the metal electrode connected to one end of the p-type stannous selenide film is a source electrode, and the metal electrode connected to one end of the n-type indium selenide film is a drain electrode.

Further, based on the same inventive concept, the invention also provides a preparation method of the photoelectric detector based on the stannous selenide/indium selenide heterojunction, wherein the preparation method comprises the following steps:

s10, cleaning the substrate by using acetone, ethanol and deionized water;

s20, preparing a p-type stannous selenide film and an n-type indium selenide film in advance;

s30, transferring the p-type stannous selenide thin film to the surface of a substrate, and then directionally transferring the n-type indium selenide thin film to the position above the p-type stannous selenide thin film through a micromechanical transfer platform and partially overlapping the p-type stannous selenide thin film;

s40, manufacturing an electrode pattern on the substrate, and preparing a metal electrode in a vapor deposition mode to obtain the photoelectric detector based on the stannous selenide/indium selenide heterojunction.

In this embodiment, the p-type stannous selenide film is prepared by a physical vapor deposition method, which includes the following specific steps: placing stannous selenide powder in a quartz boat, and placing SiO₂the/Si substrate is reversely buckled above the stannous selenide powder; and placing the quartz boat in a tube furnace, and heating and reacting under the protection of argon to prepare the p-type stannous selenide film. The n-type indium selenide thin film is prepared by a mechanical stripping method.

In some embodiments, the step of transferring the p-type stannous selenide thin film to the surface of the substrate comprises:

and transferring the p-type stannous selenide film onto a PDMS substrate, and transferring the p-type stannous selenide film from the PDMS substrate to the surface of the substrate through a micromechanical transfer platform.

In this embodiment, the PDMS (polydimethylsiloxane) substrate is a flexible substrate having viscosity, the p-type stannous selenide thin film can be bonded by using the viscosity of the PDMS substrate, and then the p-type stannous selenide thin film is transferred from the PDMS substrate to the surface of the substrate by using a micromechanical transfer platform.

The following explains the photodetector based on the stannous selenide/indium selenide heterojunction and the preparation method thereof further by specific embodiments.