A method for preparing zinc telluride nanosheets, a photoelectric device, and its preparation method and application

Abstract

The present invention provides a method for preparing zinc telluride nanosheets, as well as a photoelectric device, its preparation method, and application, belonging to the field of optoelectronic technology of semiconductor materials. The present invention first uses zinc telluride powder and tellurium powder as raw materials, and adopts physical vapor deposition to grow zinc telluride on fluorphlogopite mica sheets, thereby obtaining zinc telluride nanosheets. A heterojunction consisting of a first layer of graphene, a zinc telluride nanosheet, and a second layer of graphene is then stacked on a substrate in sequence, wherein metal electrodes are provided at both ends of the graphene, thereby obtaining a photoelectric device. The photoelectric device of the present invention has the functions of both photoelectric detection and fluorescence switching. When used as a photodetector, it has the characteristics of a wide response range, high responsiveness, and high stability. When used as a fluorescence switch, the fluorescence is completely quenched when the bias voltage reaches 8 volts. The photoelectric device has the characteristics of simple structure, high reliability, and easy manufacturing, and expands the application of two-dimensional materials in the field of optoelectronic integration.

Description

Technical Field

[0001] The present invention relates to the field of optoelectronic technology of semiconductor materials, and in particular to a method for preparing zinc telluride nanosheets, a photoelectric device, and a preparation method and application thereof. Background Art

[0002] Two-dimensional heterojunctions combine the advantages of different two-dimensional materials. They not only have the thickness of an atomic layer and strong light-matter interaction, but are also easily compatible with existing silicon-based devices. Optoelectronic devices based on two-dimensional heterojunctions have been widely studied and are expected to replace existing optoelectronic devices in many applications. At present, achieving high-speed, small size, low power consumption, and low-cost optoelectronic integrated circuits is still a huge challenge. Designing multifunctional devices based on two-dimensional heterojunctions that have both photodetection and electro-optical modulation is a feasible solution. In this way, it is expected to realize new architectures in optoelectronic integrated circuits. Various types of single-function high-performance optoelectronic devices are constantly being updated, but devices that have both excellent photodetection performance and efficient electro-optical regulation have yet to be realized. Therefore, it is of great significance to develop an optoelectronic device with the multifunctionality of photodetection and fluorescence switching and a preparation method thereof. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for preparing zinc telluride nanosheets and a photoelectric device and its preparation method and application, so as to solve the technical problem that there is no photoelectric device with both photoelectric detection and fluorescence switching functions in the prior art.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The present invention provides a method for preparing zinc telluride nanosheets, comprising the following steps:

[0006] Using zinc telluride powder and tellurium powder as raw materials, zinc telluride is grown on fluorophlogopite mica sheets by physical vapor deposition, thus obtaining zinc telluride nanosheets.

[0007] Preferably, the mass ratio of the zinc telluride powder to the tellurium powder is 1:1-2; the carrier gases used in the physical vapor deposition method are hydrogen and argon, wherein the flow rate of hydrogen is 10-30 sccm and the flow rate of argon is 60-100 sccm; the reaction temperature in the physical vapor deposition method is 900-1000°C, and the reaction time is 20-40 min.

[0008] The present invention provides a photoelectric device, comprising a heterojunction consisting of a first layer of graphene, zinc telluride nanosheets and a second layer of graphene stacked in sequence on a substrate, wherein metal electrodes are provided at both ends of the first layer of graphene and the second layer of graphene.

[0009] Preferably, the substrate is a silicon dioxide / silicon substrate, wherein the thickness of the silicon dioxide is 200 to 400 nm.

[0010] Preferably, the thickness of the zinc telluride nanosheet is 20 to 80 nm;

[0011] Preferably, the number of layers of the first graphene layer and the second graphene layer is independently 1 to 10.

[0012] Preferably, the metal electrode consists of a gold electrode and an electrode adhesion layer, wherein the electrode adhesion layer comprises a titanium electrode adhesion layer, a chromium electrode adhesion layer or a nickel electrode adhesion layer; the thickness of the metal electrode is 40 to 60 nm, wherein the thickness ratio of the gold electrode to the electrode adhesion layer is 35 to 50:5 to 10.

[0013] The present invention provides a method for preparing a photoelectric device, comprising the following steps:

[0014] (1) preparing a first layer of graphene and a second layer of graphene by mechanical exfoliation, and then stacking the first layer of graphene, zinc telluride nanosheets, and the second layer of graphene on a substrate from bottom to top to obtain a heterojunction;

[0015] (2) Electrode pattern design using electron beam exposure;

[0016] (3) Electron beam evaporation deposition is used to arrange metal electrodes on the first and second graphene layers to obtain a photoelectric device.

[0017] The present invention provides an application of a photoelectric device in detecting optical signals in the visible-infrared band.

[0018] The present invention provides an application of a photoelectric device as a fluorescence switch.

[0019] Beneficial effects of the present invention:

[0020] (1) The present invention adopts the physical vapor deposition method to stably grow two-dimensional non-layered ZnTe nanosheets, and the quality of the nanosheets is good.

[0021] (2) The optoelectronic device of the present invention combines the functions of photodetection and fluorescence switching. When used as a photodetector, it has a wide response range, high responsiveness, and high stability. When used as a fluorescence switch, fluorescence is completely quenched when the bias voltage reaches 8 volts. The optoelectronic device has the advantages of simple structure, high reliability, and easy manufacturing, expanding the application of two-dimensional materials in the field of optoelectronic integration. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the physical vapor deposition method for growing zinc telluride nanosheets in the present invention, wherein G b Represents the first layer of graphene, Gt represents the second layer of graphene, S and D represent metal electrodes;

[0023] Figure 2 A schematic diagram of a photoelectric device prepared according to the present invention;

[0024] Figure 3 The photocurrent response diagram of the optoelectronic device prepared in Example 4 under laser irradiation of different wavelengths;

[0025] Figure 4 This is a relationship diagram between the photoresponsivity R and the detectivity D* of the optoelectronic device prepared in Example 4 under laser irradiation of different wavelengths;

[0026] Figure 5 FIG4 is a diagram showing the fluorescence quenching evolution process of the photoelectric device prepared in Example 4 under bias voltage;

[0027] Figure 6 This is a fluorescence intensity diagram of the optoelectronic device prepared in Example 4 under periodic bias control. DETAILED DESCRIPTION

[0028] The present invention provides a method for preparing zinc telluride nanosheets, comprising the following steps:

[0029] Using zinc telluride powder and tellurium powder as raw materials, zinc telluride is grown on fluorophlogopite mica sheets by physical vapor deposition, thus obtaining zinc telluride nanosheets.

[0030] In the present invention, the preparation of the zinc telluride nanosheets is preferably carried out in a horizontal tube furnace, wherein the positional relationship of the zinc telluride powder, tellurium powder, and fluorphlogopite mica sheets in the horizontal tube furnace is, from near to far, tellurium powder, zinc telluride powder, and fluorphlogopite mica sheets near the carrier gas inlet end.

[0031] In the present invention, the mass ratio of the zinc telluride powder to the tellurium powder is 1:1-2, preferably 1:1; the carrier gases used in the physical vapor deposition method are hydrogen and argon, wherein the flow rate of hydrogen is 10-30 sccm, preferably 15-25 sccm, and more preferably 20 sccm; the flow rate of argon is 60-100 sccm, preferably 70-90 sccm, and more preferably 80 sccm; the reaction temperature in the physical vapor deposition method is 900-1000°C, preferably 920-980°C, and more preferably 950°C; the reaction time is 20-40 min, preferably 25-35 min, and more preferably 30 min.

[0032] The present invention provides a photoelectric device, comprising a heterojunction consisting of a first layer of graphene, zinc telluride nanosheets and a second layer of graphene stacked in sequence on a substrate, wherein metal electrodes are provided at both ends of the first layer of graphene and the second layer of graphene.

[0033] In the present invention, the substrate is a silicon dioxide / silicon substrate, wherein the thickness of the silicon dioxide is 200 to 400 nm, preferably 250 to 350 nm, and more preferably 300 nm.

[0034] In the present invention, the thickness of the zinc telluride nanosheets is 20 to 80 nm, preferably 30 to 70 nm, and more preferably 40 to 60 nm;

[0035] In the present invention, the number of layers of the first graphene layer and the second graphene layer is independently 1 to 10 layers, preferably 3 to 8 layers, and more preferably 5 layers.

[0036] In the present invention, the metal electrode is composed of a gold electrode and an electrode adhesion layer, wherein the electrode adhesion layer comprises a titanium electrode adhesion layer, a chromium electrode adhesion layer or a nickel electrode adhesion layer, preferably a titanium electrode adhesion layer or a chromium electrode adhesion layer, and further preferably a chromium electrode adhesion layer; the thickness of the metal electrode is 40 to 60 nm, preferably 42 to 58 nm, and further preferably 45 to 55 nm; wherein the thickness ratio of the gold electrode to the electrode adhesion layer is 35 to 50:5 to 10, preferably 40 to 45:5 to 9, and further preferably 45:5.

[0037] The present invention provides a method for preparing a photoelectric device, comprising the following steps:

[0038] (1) preparing a first layer of graphene and a second layer of graphene by mechanical exfoliation, and then stacking the first layer of graphene, zinc telluride nanosheets, and the second layer of graphene on a substrate from bottom to top to obtain a heterojunction;

[0039] (2) Electrode pattern design using electron beam exposure;

[0040] (3) Electron beam evaporation deposition is used to arrange metal electrodes on the first and second graphene layers to obtain a photoelectric device.

[0041] In the present invention, the substrate is preferably pretreated, and the specific steps are: ultrasonically treating the substrate in acetone, isopropanol and deionized water for 15 minutes each, and then drying the substrate for later use.

[0042] In the present invention, the first layer of graphene, zinc telluride nanosheets, and the second layer of graphene are stacked sequentially on the substrate from bottom to top, preferably by sequentially transferring the first layer of graphene, zinc telluride nanosheets, and the second layer of graphene adhered to PDMS to the target position of the substrate through a transfer platform.

[0043] When the present invention uses electron beam exposure to design the electrode pattern, a slurry coater is preferably used to sequentially and evenly spin-coat methyl methacrylate (MMA) and polymethyl methacrylate (PMMA) on a silicon dioxide / silicon substrate supporting a heterojunction. The methyl methacrylate (MMA) and polymethyl methacrylate (PMMA) are spin-coated twice, with the first spin-coating speed being 600-1000 r / min and the spin-coating time being 8-12 seconds, preferably 800 r / min and the spin-coating time being 10 seconds; the second spin-coating speed being 3800-4200 r / min and the spin-coating time being 40-60 seconds, preferably 4000 r / min and the spin-coating time being 50 seconds. Electron beam exposure is then used to denature the glue, and after development with a developer, the glue is cleaned with deionized water and dried to obtain the desired electrode pattern.

[0044] In the present invention, the acceleration voltage during the electron beam exposure process is 25-35 keV, preferably 28-32 keV, and more preferably 30 keV; the beam current is 0.1-0.3 nA, preferably 0.2 nA; the charge per unit area is 200-300 μC / cm 2 , preferably 220 to 280 μC / cm 2 , more preferably 250μC / cm 2 .

[0045] In the present invention, the vacuum degree during the electron beam evaporation deposition process is 2.0×10 -4 ~2.4×10 -4 Pa, preferably 2.1×10 -4 ~2.3×10 -4 Pa, more preferably 2.2×10 -4 Pa; the metal electrode is preferably composed of a gold electrode and a chromium electrode adhesion layer, wherein the evaporation rate of chromium is 0.2 to 0.4 A / s, preferably 0.3 A / s; the evaporation rate of gold is 0.4 to 0.6 A / s, preferably 0.5 A / s.

[0046] The present invention provides an application of a photoelectric device in detecting optical signals in the visible-infrared band.

[0047] The present invention provides an application of a photoelectric device as a fluorescence switch.

[0048] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0049] Example 1

[0050] 0.5g zinc telluride powder and 0.5g tellurium powder were placed in two quartz boats respectively. Figure 1 At the position shown, tellurium powder, zinc telluride powder and fluorphlogopite mica sheets are placed in a horizontal tube furnace from near to far, near the carrier gas inlet end, and the horizontal tube furnace is sealed, evacuated and introduced with argon. After repeating this three times, the pressure is maintained at normal pressure. Then, hydrogen and argon are continuously introduced into the horizontal tube furnace, where the flow rate of hydrogen is 20 sccm and the flow rate of argon is 100 sccm. Physical vapor deposition is then carried out at a temperature of 950°C for 30 minutes, and then the mixture is naturally cooled to room temperature to obtain zinc telluride nanosheets.

[0051] Example 2

[0052] 0.5g zinc telluride powder and 1g tellurium powder were placed in two quartz boats respectively. Figure 1 At the position shown, tellurium powder, zinc telluride powder and fluorphlogopite mica sheets are placed in a horizontal tube furnace from near to far, near the carrier gas inlet end, and the horizontal tube furnace is sealed, evacuated and introduced with argon gas. This is repeated three times and then maintained at normal pressure. Then, hydrogen and argon are continuously introduced into the horizontal tube furnace, with a hydrogen flow rate of 30 sccm and an argon flow rate of 60 sccm. Physical vapor deposition is then carried out at a physical vapor deposition temperature of 1000°C and a time of 20 minutes. The mixture is then naturally cooled to room temperature to obtain zinc telluride nanosheets.

[0053] Example 3

[0054] 0.5g zinc telluride powder and 1g tellurium powder were placed in two quartz boats respectively. Figure 1 At the position shown, tellurium powder, zinc telluride powder and fluorphlogopite mica sheets are placed in a horizontal tube furnace from near to far, near the carrier gas inlet end, and the horizontal tube furnace is sealed, evacuated and introduced with argon gas. This is repeated three times and then maintained at normal pressure. Then, hydrogen and argon are continuously introduced into the horizontal tube furnace, with a hydrogen flow rate of 10 sccm and an argon flow rate of 80 sccm. Physical vapor deposition is then performed at a physical vapor deposition temperature of 900°C and a time of 40 minutes. The mixture is then naturally cooled to room temperature to obtain zinc telluride nanosheets.

[0055] Example 4

[0056] The silica / silicon substrate was cut into 1cm x 1cm dimensions, with a thickness of 285nm. The substrate was ultrasonically treated in acetone, isopropyl alcohol, and deionized water for 15 minutes each, blown dry with a nitrogen gun, and then set aside. Graphene flakes were then arranged in an orderly manner on 3M tape and folded in half multiple times to produce few-layer graphene. The 3M tape was then applied to the cleaned silica / silicon substrate and repeatedly rubbed to ensure full contact between the graphene flakes and the substrate. The tape was removed, and the first graphene layer, consisting of four layers, was stacked on the substrate. Then, a PDMS film is covered on the zinc telluride nanosheets prepared in Example 1, and then the PDMS film with the zinc telluride nanosheets adhered is separated from the fluorphlogopite mica sheet. Then, the other side of the PDMS film without the zinc telluride nanosheets adhered is attached to a glass slide. With the help of a transfer platform, the sample is positioned, and the zinc telluride nanosheets are point-transferred onto the first layer of graphene, where the thickness of the zinc telluride nanosheets is 60 nm. Then, the residual PDMS film is removed by soaking with an organic solvent. Finally, the second layer of graphene is transferred to the zinc telluride nanosheets using the same method, where the second layer of graphene is three layers, to obtain a heterojunction.

[0057] Methyl methacrylate (MMA) was evenly spin-coated on the silicon dioxide / silicon substrate supporting the heterojunction using a spin coater at a speed of 800 r / min for 10 seconds. Methyl methacrylate (MMA) was then spin-coated at a speed of 4000 r / min. After the spin coating was completed, polymethyl methacrylate (PMMA) was heated on a heating table for 3 minutes and then spin-coated using the same method. Finally, the electrode pattern was designed using electron beam lithography, with an acceleration voltage of 30 keV, a beam current of 0.2 nA, and a charge per unit area of 250 μC / cm. 2 The exposed sample was placed in the developer for 20 seconds. After development, it was cleaned with deionized water and dried.

[0058] Finally, electron beam evaporation was used to deposit a 5 nm chromium electrode adhesion layer on both ends of the first and second graphene layers, followed by a 45 nm gold electrode to form a 50 nm thick metal electrode. The vacuum degree during electron beam evaporation was 2.2×10 -4 Pa, the deposition rate of the chromium electrode adhesion layer is 0.3A / s, and the deposition rate of the gold electrode is 0.5A / s. After the deposition is completed, PMMA is soaked in acetone to remove the gold film outside the electrode pattern to obtain a photoelectric device.

[0059] The present invention performs a performance test on the optoelectronic device prepared in Example 4. Figure 3 The photocurrent response curves of the photoelectric device prepared in Example 4 when used as a photodetector under laser irradiation of different wavelengths are shown in FIG. Figure 4The relationship between the responsivity R and the detectivity D* of the optoelectronic device prepared in Example 4 under different wavelengths of laser irradiation is shown in the figure. When the wavelength is 532 nm, R and D* reach their maximum values, which are 2 A / W and 3×10 10 Jones, indicating that it has the characteristics of wide response range, high responsiveness and high stability. Figure 5 The fluorescence scanning diagrams at different bias voltages when the photoelectric device prepared in Example 4 is used as a fluorescence switch show that as the voltage increases, the fluorescence in the central area decreases from strong to weak. When the bias voltage reaches 8V, the fluorescence is completely quenched. Figure 6 The fluorescence intensity changes with the periodic on and off of the bias voltage, indicating that fast and stable fluorescence switching function can be achieved under bias control.

[0060] Example 5

[0061] A silica / silicon substrate was cut into 1cm x 1cm dimensions, with a 200nm thick silica layer. The substrate was ultrasonically treated in acetone, isopropyl alcohol, and deionized water for 15 minutes each, blown dry with a nitrogen gun, and then set aside. Graphene flakes were then arranged on 3M tape and folded in half multiple times to form a few-layer graphene. The 3M tape was then applied to the cleaned silica / silicon substrate and repeatedly rubbed to ensure full contact between the graphene flakes and the substrate. The tape was then removed, and the first two layers of graphene were stacked on the substrate. Then, a PDMS film is covered on the zinc telluride nanosheet prepared in Example 1, and then the PDMS film with the zinc telluride nanosheet adhered is separated from the fluorphlogopite mica sheet. Then, the other side of the PDMS film without the zinc telluride nanosheet adhered is attached to a glass slide. With the help of a transfer platform, the sample is positioned, and the zinc telluride nanosheet is point-transferred onto the first layer of graphene, where the thickness of the zinc telluride nanosheet is 20 nm. Then, the residual PDMS film is soaked in an organic solvent to remove it. Finally, the second layer of graphene is transferred to the zinc telluride nanosheet using the same method, where the second layer of graphene is one layer, to obtain a heterojunction.

[0062] Methyl methacrylate (MMA) was evenly spin-coated on the silicon dioxide / silicon substrate supporting the heterojunction using a spin coater at a speed of 800 r / min for 10 seconds. Methyl methacrylate (MMA) was then spin-coated at a speed of 4000 r / min. After the spin coating was completed, polymethyl methacrylate (PMMA) was heated on a heating table for 3 minutes and then spin-coated using the same method. Finally, the electrode pattern was designed using electron beam lithography, with an acceleration voltage of 30 keV, a beam current of 0.2 nA, and a charge per unit area of 250 μC / cm. 2 The exposed sample was placed in the developer for 20 seconds. After development, it was cleaned with deionized water and dried.

[0063] Finally, electron beam evaporation was used to deposit an 8 nm chromium electrode adhesion layer on both ends of the first and second graphene layers, followed by a 35 nm gold electrode to form a metal electrode with a thickness of 43 nm. The vacuum degree during electron beam evaporation was 2.4×10 -4 Pa, the deposition rate of the chromium electrode adhesion layer is 0.2A / s, and the deposition rate of the gold electrode is 0.6A / s. After the deposition is completed, PMMA is soaked in acetone to remove the gold film outside the electrode pattern to obtain a photovoltaic device.

[0064] Example 6

[0065] A silica / silicon substrate was cut into 1cm x 1cm dimensions, with the silica layer being 400nm thick. The substrate was ultrasonically treated in acetone, isopropyl alcohol, and deionized water for 15 minutes each, blown dry with a nitrogen gun, and then set aside. Graphene flakes were then arranged in an orderly fashion on 3M tape and folded in half multiple times to produce a few-layer graphene. The 3M tape was then applied to the cleaned silica / silicon substrate and repeatedly rubbed to ensure full contact between the graphene flakes and the substrate. The tape was then removed, and the first eight-layer graphene layer was stacked on the substrate. Then, a PDMS film is covered on the zinc telluride nanosheets prepared in Example 1, and then the PDMS film with the zinc telluride nanosheets adhered is separated from the fluorphlogopite mica sheet. Then, the other side of the PDMS film without the zinc telluride nanosheets adhered is attached to a glass slide. With the help of a transfer platform, the sample is positioned, and the zinc telluride nanosheets are point-transferred onto the first layer of graphene, where the thickness of the zinc telluride nanosheets is 80 nm. The residual PDMS film is then soaked in an organic solvent to remove it. Finally, the second layer of graphene is transferred to the zinc telluride nanosheets using the same method, where the second layer of graphene is 6 layers, to obtain a heterojunction.

[0066] Methyl methacrylate (MMA) was evenly spin-coated on the silicon dioxide / silicon substrate supporting the heterojunction using a spin coater at a speed of 800 r / min for 10 seconds. Methyl methacrylate (MMA) was then spin-coated at a speed of 4000 r / min. After the spin coating was completed, polymethyl methacrylate (PMMA) was heated on a heating table for 3 minutes and then spin-coated using the same method. Finally, the electrode pattern was designed using electron beam lithography, with an acceleration voltage of 30 keV, a beam current of 0.2 nA, and a charge per unit area of 250 μC / cm. 2 The exposed sample was placed in the developer for 20 seconds. After development, it was cleaned with deionized water and dried.

[0067] Finally, electron beam evaporation was used to deposit a 10 nm chromium electrode adhesion layer on both ends of the first and second graphene layers, followed by a 50 nm gold electrode to form a 60 nm thick metal electrode. The vacuum degree during electron beam evaporation was 2.0×10 -4Pa, the deposition rate of the chromium electrode adhesion layer is 0.4 A / s, and the deposition rate of the gold electrode is 0.4 A / s. After the deposition is completed, PMMA is soaked in acetone to remove the gold film outside the electrode pattern to obtain a photovoltaic device.

[0068] As can be seen from the above embodiments, the present invention provides a method for preparing zinc telluride nanosheets, as well as a photoelectric device, its preparation method, and application. First, zinc telluride powder and tellurium powder are used as raw materials, and zinc telluride is grown on a fluorphlogopite mica sheet by physical vapor deposition to obtain zinc telluride nanosheets. Then, a heterojunction consisting of a first layer of graphene, a zinc telluride nanosheet, and a second layer of graphene is stacked in sequence on a substrate, wherein metal electrodes are provided at both ends of the graphene to obtain a photoelectric device. The photoelectric device of the present invention has the functions of both photoelectric detection and electro-optical modulation. When used as a photodetector, it has the characteristics of a wide response range, high responsiveness, and high stability. When used as a fluorescent switch, the fluorescence is completely quenched when the bias voltage reaches 8 volts. The photoelectric device has the characteristics of simple structure, high reliability, and easy manufacturing, which expands the application of two-dimensional materials in the field of optoelectronic integration.

[0069] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A photoelectric device, characterized in that: The invention relates to a heterojunction consisting of a first graphene layer, a zinc telluride nanosheet, and a second graphene layer stacked sequentially on a substrate, wherein metal electrodes are provided at both ends of the first graphene layer and the second graphene layer. The preparation method of the zinc telluride nanosheet comprises the following steps: Using zinc telluride powder and tellurium powder as raw materials, zinc telluride is grown on fluorophlogopite mica sheets by physical vapor deposition, thus obtaining zinc telluride nanosheets. The thickness of the zinc telluride nanosheet is 20-80 nm.

2. The optoelectronic device according to claim 1, wherein: The mass ratio of the zinc telluride powder to the tellurium powder is 1:1-2; the carrier gases used in the physical vapor deposition method are hydrogen and argon, wherein the flow rate of hydrogen is 10-30 sccm and the flow rate of argon is 60-100 sccm; the reaction temperature in the physical vapor deposition method is 900-1000°C, and the reaction time is 20-40 minutes.

3. The optoelectronic device according to claim 1, wherein: The substrate is a silicon dioxide / silicon substrate, wherein the thickness of the silicon dioxide is 200-400 nm.

4. The optoelectronic device according to claim 3, characterized in that The number of layers of the first graphene layer and the second graphene layer is independently 1 to 10.

5. The optoelectronic device according to claim 1, 3 or 4, characterized in that: The metal electrode consists of a gold electrode and an electrode adhesion layer, wherein the electrode adhesion layer comprises a titanium electrode adhesion layer, a chromium electrode adhesion layer or a nickel electrode adhesion layer; the thickness of the metal electrode is 40 to 60 nm, wherein the thickness ratio of the gold electrode to the electrode adhesion layer is 35 to 50:5 to 10.

6. The method for preparing a photoelectric device according to any one of claims 1 to 5, characterized in that: The following steps are involved: (1) preparing a first layer of graphene and a second layer of graphene by mechanical exfoliation, and then stacking the first layer of graphene, zinc telluride nanosheets, and the second layer of graphene on a substrate from bottom to top to obtain a heterojunction; (2) Electrode pattern design using electron beam exposure; (3) Electron beam evaporation deposition is used to arrange metal electrodes on the first and second graphene layers to obtain a photoelectric device.

7. Use of the optoelectronic device according to any one of claims 1 to 5 in detecting optical signals in the visible-infrared band.

8. Use of the optoelectronic device according to any one of claims 1 to 5 as a fluorescent switch.

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