A tellurium nanowire / rhenium disulfide mixed-dimensional polarization photodetector and its preparation method

Abstract

The present invention relates to a mixed-dimensional polarization photodetector of tellurium nanowires / rhenium disulfide and a preparation method thereof. The photodetector includes a substrate, a thin layer of ReS2 disposed on the substrate, tellurium nanowires disposed on the thin layer of ReS2, electrode layers are respectively disposed on the thin layer of ReS2 and one end of the tellurium nanowires, and the thin layer of ReS2 is grown by an optimized CVD process, the tellurium nanowires are grown by a PVD process, and the thin layer of ReS2 and the tellurium nanowires are transferred to a target substrate by a PVD / PDMS dry transfer technique to form a one-dimensional / two-dimensional mixed-dimensional heterojunction; metal electrodes are disposed at both ends of the heterojunction to fabricate a polarization photodetector. The detector exhibits excellent photovoltaic effects, the dynamic light response time is about 20 ms, and it also exhibits superior polarization-sensitive light detection performance, with an anisotropic photocurrent ratio of 2.7.

Description

Technical Field

[0001] The present invention relates to the field of photoelectric detection technology, and in particular to a tellurium nanowire / rhenium disulfide mixed-dimensional polarization photoelectric detector and a preparation method thereof. Background Art

[0002] Two-dimensional materials such as graphene and transition metal dichalcogenides have attracted extensive attention in the past decade due to their unique electronic structures and physical properties. At the same time, van der Waals heterostructures composed of two-dimensional materials and traditional semiconductors have always shown excellent optoelectronic properties and have attracted much attention in recent years. As a new member of the transition metal chalcogenides (TMDs) family, rhenium disulfide (ReS2) has many exotic properties, such as strong in-plane anisotropy, weak interlayer coupling, and lack of indirect to direct gap transition. In recent years, two-dimensional tellurium (Te) has become a promising p-type material compared with other single-element two-dimensional materials (bP, b-As, Bi, etc.) due to its high mobility, narrow bandgap, high light absorption, and extraordinary air stability. Chemical vapor deposition (CVD) is a process in which gaseous or vaporous substances react in the gas phase or at the gas-solid interface to generate solid deposits, which can obtain thin film coatings with high purity, good density, low residual stress, and good crystallization. Physical vapor deposition (PVD) is a method of vaporizing the coating material by physical methods (such as evaporation, sputtering, etc.) and depositing a film on the surface of a substrate. Therefore, the present invention provides a method of generating high-quality rhenium disulfide (ReS2) by chemical vapor deposition (CVD) and high-quality tellurium (Te) by physical vapor deposition (PVD) and preparing a tellurium (Te) nanowire / rhenium disulfide (ReS2) mixed-dimensional heterojunction photodetector and testing its polarization-sensitive light detection performance. Summary of the invention

[0003] In view of the technical problems existing in the prior art, the purpose of the present invention is to provide a tellurium nanowire / rhenium disulfide mixed-dimensional polarization photodetector and a preparation method thereof. The photodetector uses one-dimensional tellurium nanowires and two-dimensional rhenium disulfide thin layers to construct a mixed-dimensional heterojunction, which combines the advantages of the two material systems and exhibits excellent photoelectric performance and polarization-sensitive light detection capabilities. In the preparation method, a high-quality tellurium nanowire is prepared by a PVD process, and a high-quality rhenium disulfide thin film is prepared by a CVD process. The rhenium disulfide thin layer and the tellurium nanowire are transferred to a target substrate by a PVA dry transfer technique to obtain a tellurium nanowire / rhenium disulfide mixed-dimensional heterojunction. A type II pn heterojunction is formed on the interface of the ReS2 and Te, which improves the injection and separation efficiency of photoexcited electron-hole pairs, and improves the photovoltaic properties and photoelectric performance of the photodetector.

[0004] Based on the above characteristics, the present invention at least provides the following technical solutions:

[0005] A method for preparing a tellurium nanowire / rhenium disulfide mixed-dimensional polarization photodetector comprises the following steps:

[0006] A horizontal tube furnace and CVD process were used to grow two-dimensional ReS2;

[0007] The PVD process was used to grow Te nanowires in a tube furnace;

[0008] The PVA dry transfer process was used to transfer a ReS2 thin layer with a thickness of 1 to 50 nm onto a SiO2 / Si substrate;

[0009] The PVA dry transfer process was used to transfer the Te nanowires onto the ReS2 thin layer to form a tellurium nanowire / rhenium disulfide mixed-dimensional heterojunction.

[0010] An electrode is fabricated on one end of the Te nanowire and the ReS2 thin layer.

[0011] Further, the steps of using a horizontal tube furnace and a CVD process to grow two-dimensional ReS2 include weighing precursor sulfur powder and ReO3 powder with a mass ratio of 100 to 2000, placing them in a quartz boat respectively, placing the quartz boat containing ReO3 powder in the middle of the horizontal tube furnace, placing the quartz boat containing sulfur powder in the upstream section of the horizontal tube furnace near the tube mouth, and placing the growth substrate directly above the ReO3 quartz boat. First, use high-purity argon gas to exhaust the air in the quartz tube; then heat to 600-800°C within 45-60 minutes, and maintain the temperature for 15-20 minutes under a constant flow of 80-100sccm high-purity argon gas; finally, cool to room temperature with the furnace. The two-dimensional ReS2 grown by the chemical vapor deposition method of the present invention has controllable thickness and size, high purity, good density, and good crystallization.

[0012] Furthermore, the mass ratio of the precursor sulfur powder to ReO3 powder is 300 to 500.

[0013] Furthermore, the step of using the PVD process to grow Te nanowires in a tube furnace includes placing high-purity Te powder in a quartz boat, then placing the quartz boat in the middle of the tube furnace, placing the growth substrate in the downstream area of ​​the gas flow, and then in an oxygen-free environment, setting the tube furnace to heat to 450-500°C within 25-30 minutes, introducing a mixed gas of argon and hydrogen with a gas flow rate of 100-500sccm, maintaining the growth time for 1-3 minutes, then turning off the gas, and rapidly cooling in the air. In this step, the heating temperature of 450-500°C is relatively mild compared to the existing heating temperature, and the quality of the prepared Te nanowires is good.

[0014] Furthermore, the step of transferring the ReS2 thin layer to the SiO2 / Si substrate includes selecting a ReS2 thin layer with a thickness of 1 to 50 nm, transferring the ReS2 thin layer to the SiO2 / Si substrate using PVA / PDMS, then heating at 90 to 110°C to separate the PDMS from the PVA, and then separating the PVA from the SiO2 / Si substrate.

[0015] Furthermore, the step of transferring the Te nanowires to the ReS2 thin layer includes selecting Te nanowires with a diameter of 10 to 200 nm, transferring the Te nanowires to the above-mentioned ReS2 thin layer using PVA / PDMS, then heating at 90 to 110°C to separate PDMS from PVA, and then separating PVA from the SiO2 / Si substrate to obtain a tellurium nanowire / rhenium disulfide mixed-dimensional heterojunction.

[0016] Furthermore, the step of making the electrode includes evaporating a 40nm to 80nm Au layer on one end of the tellurium nanowire and on the ReS2 thin layer, followed by annealing at 100 to 200°C for 20 to 60 minutes.

[0017] Another aspect of the present invention provides a tellurium nanowire / rhenium disulfide mixed-dimensional polarization photodetector, comprising: a substrate; a thin layer of ReS2, disposed on the substrate; a tellurium nanowire, disposed on the thin layer of ReS2, the tellurium nanowire and the thin layer of ReS2 forming a one-dimensional / two-dimensional mixed-dimensional heterojunction; a first electrode and a second electrode, respectively disposed on one end of the tellurium nanowire and the thin layer of ReS2.

[0018] Furthermore, the diameter of the tellurium nanowire is 10 to 200 nm.

[0019] Furthermore, the thickness of the few-layer ReS2 is 1 to 50 nm.

[0020] Furthermore, the substrate is a SiO2 / Si substrate.

[0021] Furthermore, the electrode is made of an Au layer, and the thickness of the Au layer is 40 to 80 nm.

[0022] Compared with the prior art, the present invention has at least the following beneficial effects:

[0023] The present invention selects tellurium nanowires and rhenium disulfide, both of which have the advantages of strong in-plane anisotropy, high mobility, narrow band gap, high light absorption and extraordinary air stability, to construct a tellurium nanowire / rhenium disulfide heterojunction to form a mixed-dimensional polarization photodetector. A type II pn heterojunction is formed on the interface of ReS2 and Te, which improves the injection and separation efficiency of photoexcited electron-hole pairs, improves the photovoltaic properties and photoelectric performance of the photodetector, and the detector also exhibits excellent polarization-sensitive light detection performance.

[0024] In addition, in the preparation method provided by the present invention, a PVD process is selected, and high-quality tellurium nanowires are obtained by optimizing the process. At the same time, an optimized CVD process is selected to prepare a high-quality rhenium disulfide thin film. The high-quality rhenium disulfide thin layer and tellurium nanowires are transferred to the target substrate through the PVA dry transfer technology, and a high-quality tellurium nanowire / rhenium disulfide mixed-dimensional heterojunction is obtained, which improves the injection and separation efficiency of photoexcited electron-hole pairs and improves the photovoltaic properties and photoelectric performance of the photodetector.

[0025] The photodetector prepared by the present invention has a photovoltaic effect and can be used as a self-driven photodetector. In one embodiment, the dynamic light response time of the photodetector is about 20ms, and the anisotropic photocurrent ratio is 2.7, which is conducive to promoting the further development and application of two-dimensional CVD-ReS2, one-dimensional PVD-Te nanowires and their mixed-dimensional heterojunctions in the field of photoelectric detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Optical image of the Te-ReS2 heterojunction photodetector.

[0027] Figure 2 In the figure, (a) is the optical image of the ReS2 thin film grown by CVD process; (b) is the Raman spectrum of the ReS2 thin film.

[0028] Figure 3 In the figure, (a) is the optical image of Te nanowires grown by PVD process; (b) is the Raman spectrum of Te nanowires.

[0029] Figure 4 This is a graph showing the light response of the Te-ReS2 heterojunction photodetector changing over time under illumination.

[0030] Figure 5 This is the light response time diagram of the Te-ReS2 heterojunction photodetector.

[0031] Figure 6 is the normalized angle-resolved photocurrent in polar coordinates, and the fitting result is obtained by the sine function. DETAILED DESCRIPTION

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings of the present invention. The described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, other embodiments obtained by ordinary technicians in this field without creative work are all within the scope of protection of the present invention. The experimental methods described in the following embodiments are all conventional methods unless otherwise specified; the reagents and materials, unless otherwise specified, can be obtained from public commercial channels.

[0033] Spatially relative terms such as "below," "beneath," "below," "above," "upper," etc. are used in this specification to explain the positioning of one element relative to a second element. These terms are intended to encompass different orientations of the device in addition to different orientations than those depicted in the figures.

[0034] In addition, the use of terms such as "first", "second", etc. to describe various elements, layers, regions, sections, etc. is not intended to be limiting. The use of "having", "containing", "including", "comprising", etc. is open-ended, indicating the presence of the stated elements or features, but does not exclude additional elements or features. Unless the context clearly states otherwise.

[0035] An embodiment of the present invention provides a tellurium nanowire / rhenium disulfide mixed-dimensional polarization photodetector, which includes a substrate, a thin layer of ReS2, a tellurium nanowire and an electrode. The substrate is a SiO2 / Si substrate, and the thin layer of ReS2 is disposed on the SiO2 / Si substrate, and the thickness of the thin layer of ReS2 is 1 to 50 nm. The thin layer of ReS2 is grown by CVD process, and then transferred to a target substrate by PVA dry method, and the target substrate is, for example, a SiO2 / Si substrate.

[0036] The tellurium nanowire is arranged on a thin layer of ReS2. The thin layer of ReS2 and the tellurium nanowire form a one-dimensional / two-dimensional mixed-dimensional heterojunction. The tellurium nanowire is grown by a PVD process and then transferred to a target substrate by a PVA dry method. The target substrate is, for example, a SiO2 / Si substrate. The diameter of the tellurium nanowire is 10 to 200 nm. Electrodes are arranged on one end of the tellurium nanowire and on the thin layer of ReS2, respectively. The electrode is, for example, an Au layer, and the thickness of the Au layer is 40 to 80 nm.

[0037] The detector exhibits excellent photovoltaic effect, a dynamic light response time of about 20ms, and excellent polarization-sensitive light detection performance, anisotropic photocurrent ratio (I ph-peak / I ph-valley ) reached 2.7.

[0038] Figure 1The figure shows a Te / ReS2 photodetector prepared according to an embodiment of the present invention, in which high-quality rhenium disulfide (ReS2) is generated by chemical vapor deposition (CVD) and high-quality tellurium (Te) is generated by physical vapor deposition (PVD), and a mixed-dimensional photodetector of tellurium (Te) nanowire / rhenium disulfide (ReS2) heterojunction is obtained by transfer preparation.

[0039] Due to the formation of a type II pn heterojunction at the interface of ReS2 and Te, the injection and separation efficiency of photoexcited electron-hole pairs is improved, thereby enhancing the photovoltaic properties and photoelectric performance of the photodetector. Figure 2 In the figure, (a) shows the optical image of rhenium disulfide (ReS2) generated by chemical vapor deposition (CVD); (b) shows the Raman spectrum of rhenium disulfide (ReS2) generated by chemical vapor deposition (CVD), which is consistent with previous reports and indicates the high crystalline quality of the generated rhenium disulfide (ReS2). Figure 3 In the figure, (a) shows the optical image of tellurium (Te) generated by physical vapor deposition (PVD); (b) shows the Raman spectrum of tellurium (Te) generated by physical vapor deposition (PVD), which is consistent with previous reports and indicates that the crystalline quality of the generated tellurium (Te) is high.

[0040] Figure 4 The light response of the Te-ReS2 heterojunction photodetector changes with time under illumination, indicating that the photodetector has good reliability, stability and fast speed. bias =0V and Vg=0V, a large photocurrent was generated under the irradiation of 4mW light power at 635nm wavelength, indicating that the device has a photovoltaic effect; due to the photovoltaic effect, the heterojunction device can also be used as a self-driven photodetector. Figure 5 The dynamic photoresponse of the device is shown, with rise and decay times of approximately 20 ms.

[0041] The Te nanowire / ReS2 thin layer mixed-dimensional polarization photodetector exhibits superior polarization-sensitive light detection performance, and obtains significant anisotropic photoresponse under 635nm illumination and 0V bias conditions. This shows that the Te nanowire / ReS2 thin layer device can identify the differences between different polarization angles of the incident light, thereby improving the signal-to-noise ratio and obtaining more and clearer physical surface information. In order to more clearly observe this polarization-dependent light response, we extracted the normalized polarization angle-dependent photocurrent and plotted it on polar coordinates, as shown in Figure 2. Figure 6 The points are fitted with a sine function, showing a double-lobed shape. ph-peak / I ph-valley ) is 2.7. This hybrid 1D / 2D heterostructure overcomes the inherent limitations of a single material, achieves new performance, and opens up new avenues for building multifunctional optoelectronic devices.

[0042] In order to make the mixed-dimensional polarization photoelectric detector of the present invention clearer, the preparation method of the detector is described in detail below.

[0043] First, the SiO2 / Si growth substrate was soaked in acetone solution, isopropanol solution and deionized water respectively, and ultrasonicated for 5 minutes after each soaking.

[0044] Then, a horizontal tube furnace and CVD process are used to carry out the controllable growth of two-dimensional ReSe2. First, weigh an appropriate amount of precursor materials ReO3 powder 10mg and sulfur powder 5g, and place them in a quartz boat respectively. Place the quartz boat containing ReO3 powder in the middle of the tube furnace, and place the quartz boat containing sulfur powder in the upstream section near the tube mouth. Place the cleaned SiO2 / Si substrate directly above the quartz boat containing ReO3. Before heating, use high-purity argon (Ar) to exhaust the air in the quartz tube. Then heat to 750°C within 50 minutes, and maintain the highest temperature for 15 minutes under a constant flow of 80sccm high-purity argon. Finally, cool to room temperature in the furnace.

[0045] Synthesis of Te nanowires: High-quality Te nanowires were grown in a tube furnace using a PVD process. High-purity Te powder (99.999%) was placed in the center of a quartz boat, which was then placed in the center of the tube furnace, and the SiO2 / Si growth substrate was placed in the downstream area. 300 sccm of argon (Ar) was introduced into the quartz tube and flushed for 10 minutes to provide an oxygen-free environment. When the tube furnace was set to heat to 490°C within 30 minutes, a mixed gas of argon and hydrogen was introduced, with a total gas flow of 200 sccm. At this point, high-density Te vapor was brought to the growth substrate, and the growth time was maintained for 3 minutes. After the growth was completed, the gas was immediately turned off and the furnace cover was lifted for rapid cooling.

[0046] Select the above-mentioned ReS2 thin layer with a thickness of 1 to 50 nm, use PVA / PDMS to stick the ReS2 thin layer on the transfer platform, transfer it to the SiO2 / Si substrate, separate the PDMS and PVA after heating at 100°C, then place the substrate in dimethyl sulfoxide at 60°C and soak for 15 minutes to separate the PVA and SiO2 / Si substrate, wash it with deionized water and blow dry it with a nitrogen gun, at this time the ReS2 thin layer is transferred to the SiO2 / Si substrate.

[0047] Select Te nanowires with a diameter of 10 to 200 nm. Use PVA / PDMS to transfer the Te nanowires to the above ReS2 thin layer, separate the PDMS and PVA after heating at 100°C, then place the substrate in dimethyl sulfoxide at 60°C and soak for 15 minutes to separate the PVA and SiO2 / Si substrate, and then wash with deionized water and blow dry with a nitrogen gun. A mixed-dimensional heterojunction of tellurium (Te) nanowires / rhenium disulfide (ReS2) is obtained.

[0048] The prepared tellurium (Te) nanowire / rhenium disulfide (ReS2) heterojunction was placed on a coater for coating, and the photoresist was dropped on the substrate. After coating, the coater was heated at 100°C for 5 minutes in the absence of light.

[0049] Then, the substrate after the glue baking is placed in a photolithography machine to photolithography electrodes, and the electrodes are photolithographyed at both ends of the thin layer ReS2 and Te nanowire materials respectively.

[0050] Electron beam evaporation was performed on the photolithographic electrodes to deposit a 50nm Au layer. Then, the photoresist was removed by soaking in acetone for 10 minutes, and water was sucked out using a needle. As the photoresist was dissolved by acetone, the gold film also fell off due to the rinsing operation. After the substrate was cleaned, it was placed in deionized water. After the water on the silicon wafer surface was blown clean with a nitrogen gun, a mixed-dimensional polarization photodetector was obtained. The device was annealed in a glove box at 150°C for 30 minutes to improve the contact quality between the material and the metal electrode.

[0051] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for preparing a tellurium nanowire / rhenium disulfide mixed-dimensional polarization photodetector, characterized in that: The following steps are involved: A horizontal tube furnace and a CVD process are used to grow two-dimensional ReS2, including weighing precursor sulfur powder and ReO3 powder with a mass ratio of 100 to 2000, placing them in quartz boats respectively, placing the quartz boat containing ReO3 powder in the middle of the horizontal tube furnace, placing the quartz boat containing sulfur powder in the upstream section of the horizontal tube furnace near the tube mouth, and placing the growth substrate directly above the ReO3 quartz boat. First, use high-purity argon gas to exhaust the air in the quartz tube; then heat to 600-800°C within 45-60 minutes, and maintain the temperature for 15-20 minutes under a constant flow of 80-100 sccm high-purity argon gas; finally, cool to room temperature with the furnace; A PVD process is used to grow Te nanowires in a tube furnace, including placing high-purity Te powder in a quartz boat, then placing the quartz boat in the middle of the tube furnace, placing a SiO2 / Si growth substrate in the downstream area of ​​the gas flow, and then setting the tube furnace to heat to 450-500°C within 25-30 minutes in an oxygen-free environment, introducing a mixed gas of argon and hydrogen with a gas flow rate of 100-500sccm, maintaining the growth time for 1-3 minutes, and then turning off the gas and rapidly cooling in air; The PVA dry transfer process was used to transfer a ReS2 thin layer with a thickness of 1 to 50 nm onto a SiO2 / Si substrate; The PVA dry transfer process was used to transfer Te nanowires onto the ReS2 thin layer to form a tellurium nanowire / rhenium disulfide mixed-dimensional heterojunction. A first electrode and a second electrode are respectively made on one end of the Te nanowire and the ReS2 thin layer, wherein the first electrode is not in contact with the ReS2 thin layer, and the second electrode is not in contact with the Te nanowire.

2. The preparation method according to claim 1, characterized in that: In the step of growing two-dimensional ReS2 using a horizontal tube furnace and CVD process, the mass ratio of the precursor sulfur powder and ReO3 powder is 300 to 500.

3. The preparation method according to claim 1 or 2, characterized in that: The step of transferring the ReS2 thin layer to the SiO2 / Si substrate comprises: selecting a ReS2 thin layer with a thickness of 1 to 50 nm, transferring the ReS2 thin layer to the SiO2 / Si substrate using PVA / PDMS, then heating at 90 to 110° C. to separate the PDMS from the PVA, and then separating the PVA from the SiO2 / Si substrate; The step of transferring the Te nanowires to the ReS2 thin layer includes selecting Te nanowires with a diameter of 10 to 200 nm, transferring the Te nanowires to the above-mentioned ReS2 thin layer using PVA / PDMS, then heating at 90 to 110°C to separate PDMS from PVA, and then separating PVA from the SiO2 / Si substrate to obtain a tellurium nanowire / rhenium disulfide mixed-dimensional heterojunction.

4. The preparation method according to claim 3, characterized in that: The steps of making the electrode include evaporating a 40nm to 80nm Au layer at one end of the tellurium nanowire and on the ReS2 thin layer, followed by annealing at 100 to 200°C for 20 to 60 minutes.

5. A tellurium nanowire / rhenium disulfide mixed-dimensional polarization photodetector obtained by the preparation method according to any one of claims 1 to 4, characterized in that: include: substrate; A thin layer of ReS2, disposed on the substrate; A tellurium nanowire is disposed on the thin layer of ReS2, wherein the tellurium nanowire and the thin layer of ReS2 form a one-dimensional / two-dimensional mixed-dimensional heterojunction; The first electrode and the second electrode are respectively disposed on one end of the tellurium nanowire and the thin layer ReS2.

6. The photodetector according to claim 5, characterized in that: The diameter of the tellurium nanowire is 10-200 nm.

7. The photodetector according to claim 5 or 6, characterized in that: The thickness of the thin layer ReS2 is 1-50 nm.

8. The photodetector according to claim 7, characterized in that The substrate is SiO2 / Si substrate.

9. The photodetector according to claim 7, characterized in that: The electrode is made of an Au layer, and the thickness of the Au layer is 40-80 nm.

Images