Rhenium diselenide, black phosphorus and arsenic heterojunction photoelectric detector and preparation method thereof

Abstract

The invention discloses a rhenium diselenide, black phosphorus and arsenic heterojunction photoelectric detector and a preparation method thereof, the rhenium diselenide, black phosphorus and arsenic heterojunction photoelectric detector comprises a rigid substrate, an AsP sheet, a ReSe2 sheet, a source electrode and a drain electrode, the AsP sheet and the ReSe2 sheet are located on the rigid substrate, the AsP sheet and the ReSe2 sheet are partially overlapped, the source electrode and the drain electrode are located on the rigid substrate, and the source electrode and the drain electrode are located on the rigid substrate. The source electrode is connected with the AsP slice, and the drain electrode is connected with the ReSe2 slice. The invention has the advantage of high responsivity to visible light.

Description

Technical Field

[0001] The present invention belongs to the field of photoelectric detectors, and in particular relates to a rhenium diselenide / arsenic black phosphorus (ReSe2 / AsP) heterojunction photoelectric detector and a preparation method thereof. Background Art

[0002] Photodetectors are devices that react to light signals through electrical signals. They are core functional devices in the field of optoelectronic devices and have broad application prospects in many fields such as optical communications, video imaging, and medical detection. Currently, GeSi / Si, GaAs / GaAlAs, HgCdTe, PtSi, and GaN photodetectors are the main ones, but these photodetectors also have different defects. For example, GeSi / Si infrared focal plane arrays can only work in the far infrared band, and the external quantum efficiency is extremely low; GaN detectors are used for the detection of visible light-invisible ultraviolet wavelengths, but the response is extremely low, which also limits the space for production.

[0003] Two-dimensional layered materials have attracted much attention due to their atomically flat surfaces, unique structures and excellent physical properties, and are widely used in electronics, optoelectronics, energy storage and sensors. Among the many two-dimensional semiconductors, transition metal dichalcogenides (TMDCs) are excellent candidates for building photodetectors because of their flexible bandgap properties, high light absorption and strong light-matter interaction. As a typical TMDCs semiconductor, ReSe2 nanosheets with twisted triclinic structure and ambipolar transport properties have excellent optical and electrical properties and are a promising two-dimensional material. However, the wide depletion barrier for electron-hole recombination at the interface is hindered, and the performance of photodetectors based on 2DReSe2 is also limited due to the concentration imbalance between electrons and holes. To address this problem, the responsivity of ReSe2 is usually improved by forming a heterojunction.

[0004] In addition, a literature has reported a ReSe2 / WSe2 heterojunction photodetector, but the photoresponsivity is only 0.28A / W (Tian X, Liu Y. Van der Waals heterojunction ReSe2 / WSe2 polarization-resolved photodetector[J]. Journal of Semiconductors, 2021, 42(3):032001.). Summary of the invention

[0005] In order to solve the problem of low responsiveness of the above-mentioned existing photodetectors to visible light, the present invention provides a rhenium diselenide / black phosphorus arsenic heterojunction photodetector and a preparation method thereof.

[0006] The rhenium diselenide / black phosphorus arsenic heterojunction photodetector described in the present invention includes a rigid substrate, an AsP thin sheet, a ReSe2 thin sheet, a source electrode, and a drain electrode. The AsP thin sheet and the ReSe2 thin sheet are located on the rigid substrate, and the AsP thin sheet and the ReSe2 thin sheet partially overlap. The source electrode and the drain electrode are located on the rigid substrate, and the source electrode is connected to the AsP thin sheet, and the drain electrode is connected to the ReSe2 thin sheet.

[0007] The rigid substrate is any one of Si / SiO2, quartz glass, sapphire, and mica.

[0008] The thickness of the AsP flake is 1 nm to 200 nm.

[0009] The thickness of the ReSe2 flakes is 1nm to 200nm.

[0010] The source electrode and the drain electrode are both conventionally used source electrodes and drain electrodes, for example, one or a combination of Cr, Ti, Ni, Au, Pd, Pt or Ag; the thickness of the source electrode and the drain electrode is 50nm to 80nm. The source electrode and the drain electrode are preferably Cr / Au.

[0011] The present invention also provides a method for preparing the above-mentioned rhenium diselenide / black phosphorus arsenic heterojunction photoelectric detector, comprising the following steps:

[0012] 1) ultrasonically cleaning the rigid substrate with acetone, ethanol and deionized water in sequence and drying it;

[0013] 2) Prepare AsP flakes and transfer them to a rigid substrate;

[0014] 3) Prepare ReSe2 thin sheets and transfer them to PDMS;

[0015] 4) Directed transfer of multilayer ReSe2 sheets on PDMS to AsP sheets;

[0016] 5) defining electrode patterns, preparing source and drain electrodes on a rigid substrate, and forming a rhenium diselenide / black phosphorus arsenic heterojunction photodetector.

[0017] In step 1, the ultrasonic cleaning time is 10 to 20 minutes.

[0018] In step 5, the electrode pattern is defined using any method selected from ultraviolet photolithography, electron beam exposure or laser direct writing; the source electrode and the drain electrode are prepared using any method selected from thermal evaporation, electron beam evaporation or magnetron sputtering and a lift-off process.

[0019] Beneficial effects: The present invention utilizes the characteristics of two-dimensional van der Waals materials without surface dangling bonds to prepare the ReSe2 / AsP two-dimensional semiconductor heterojunction photodetector, which increases the responsiveness to visible light from 0.0039A / W of ReSe2 to 4.4A / W of ReSe2 / AsP. Compared with the existing ReSe2 / WSe2 heterojunction photodetector of 0.28A / W, the responsiveness to visible light is significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic structural diagram of the ReSe2 / AsP heterojunction photodetector of the present invention;

[0021] Figure 2 is an optical micrograph of a ReSe2 / AsP heterojunction photodetector prepared in an embodiment of the present invention;

[0022] Figure 3 1 is a calculated responsivity curve of the ReSe2 / AsP heterojunction photodetector prepared in an embodiment of the present invention under irradiation with different light intensities at 532 nm;

[0023] Figure 4 This is the calculated responsivity curve of the ReSe2 photodetector under 532nm light intensity. DETAILED DESCRIPTION

[0024] The present invention will now be further described in detail by way of embodiments in conjunction with the accompanying drawings, but the present invention is not limited to the embodiments.

[0025] The present invention is a ReSe2 / AsP heterojunction photodetector having a structure as follows Figure 1 As shown, it includes a rigid substrate (the upper layer is SiO2 layer 1, and the lower layer is Si layer 2), an AsP thin film 3, a ReSe2 thin film 4, a source electrode 5, and a drain electrode 6. The AsP thin film 3 and the ReSe2 thin film 4 are located on the rigid substrate, and the AsP thin film 3 and the ReSe2 thin film 4 partially overlap. The source electrode 5 and the drain electrode 6 are located on the rigid substrate, and the source electrode 5 is connected to the AsP thin film 3, and the drain electrode 6 is connected to the ReSe2 thin film 4.

[0026] Example

[0027] The ReSe2 / AsP heterojunction photodetector of the present invention is prepared by the following steps.

[0028] 1) Prepare a rigid substrate

[0029] A rigid substrate with a thickness of 300 nm (the upper layer is a SiO2 layer, the lower layer is a Si layer, i.e., Si / SiO2) was selected, and ultrasonically cleaned with acetone, ethanol, and deionized water for 10 min respectively with an ultrasonic power of 100 W, and then dried with a nitrogen gun for later use.

[0030] 2) AsP thin film preparation and transfer

[0031] Place the AsP single crystal on the prepared 3M white tape, stick it repeatedly 5 to 6 times, use the adhesion of the tape to mechanically peel it off, then use Schott blue tape to transfer it, and finally transfer the prepared AsP flakes to the Si / SiO2 rigid substrate. Select the AsP flakes with a thickness of about 9nm that are close to the color of the rigid substrate under a light microscope.

[0032] 3) ReSe2 thin film preparation and transfer

[0033] A multilayer ReSe2 sheet with a thickness of 6 nm was prepared by the same method as described above, and it was tightly adhered to a PDMS (polydimethylsiloxane) film. After the tape was removed, the ReSe2 sheet was attached to the PDMS film.

[0034] 4) Preparation of 2D ReSe2 / AsP van der Waals heterojunction

[0035] The other side of the PDMS with the ReSe2 flakes was adhered to the upper surface of the glass slide, the glass slide was rotated so that the PDMS with the ReSe2 flakes faced downward, and the glass slide was mounted on a microscope-assisted three-dimensional displacement platform.

[0036] Through microscopic observation, the selected AsP sheet with a certain thickness is moved to the center of the field of view, aligned with the ReSe2 sheet on the PDMS that needs to be transferred, and the ReSe2 sheet on the PDMS film is gradually moved closer to the AsP sheet using a three-dimensional displacement platform.

[0037] After heating the rigid substrate to about 70°C, stop heating and gradually move the ReSe2 sheet to make it in close contact with the AsP sheet, continue heating to 80°C, and wait for 5 minutes. Lift the glass slide to separate the ReSe2 sheet from the PDMS film and partially stack it with the AsP sheet to form a ReSe2 / AsP van der Waals heterojunction.

[0038] 5) Fabrication of two-dimensional ReSe2 / AsP van der Waals heterojunction transistors

[0039] The van der Waals heterojunction prepared above was spin-coated with photoresist PMMA (polymethyl methacrylate) by a coater and heated at 150° C. for 5 minutes. Each electrode pattern was precisely positioned and exposed by electron beam exposure, followed by development and fixing.

[0040] 3 nm of Cr and 60 nm of Au are deposited by electron beam evaporation to form a source electrode and a drain electrode both of which are Cr / Au; then the electrodes are cleaned in acetone to remove the photoresist (i.e., the lift-off process), and then dried with a nitrogen gun to form a ReSe2 / AsP heterojunction transistor (i.e., a ReSe2 / AsP heterojunction photodetector), as shown in FIG. Figure 2 shown.

[0041] Photoelectric performance test

[0042] The ReSe2 / AsP heterojunction transistor sample was irradiated with lasers of different powers at a wavelength of 532nm, and its current was tested at both ends of the source electrode and the drain electrode. Figure 3 It can be seen that the above ReSe2 / AsP heterojunction transistor shows a higher responsivity in the visible light region than a single ReSe2 two-dimensional semiconductor photodetector ( Figure 4 ) has been greatly improved. The results show that the van der Waals heterojunction formed by stacking two-dimensional ReSe2 and narrow-bandgap AsP significantly improves the visible light response.

[0043] The above-mentioned technologies not specifically mentioned are all referred to the prior art.

[0044] Based on the above-mentioned ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above-mentioned description. The technical scope of the present invention is not limited to the contents of the specification.

Claims

1. A rhenium diselenide / black phosphorus arsenic heterojunction photodetector, characterized in that: It includes a rigid substrate, an AsP thin sheet, a ReSe2 thin sheet, a source electrode, and a drain electrode. The AsP thin sheet and the ReSe2 thin sheet are located on the rigid substrate. The AsP thin sheet and the ReSe2 thin sheet partially overlap. The source electrode and the drain electrode are located on the rigid substrate. The source electrode is connected to the AsP thin sheet, and the drain electrode is connected to the ReSe2 thin sheet.

2. The rhenium diselenide / black phosphorus arsenic heterojunction photodetector according to claim 1, characterized in that: The rigid substrate is any one of Si / SiO2, quartz glass, sapphire, and mica.

3. The rhenium diselenide / black phosphorus arsenic heterojunction photodetector according to claim 1, characterized in that: The thickness of the AsP flake is 1 nm to 200 nm.

4. The rhenium diselenide / black phosphorus arsenic heterojunction photodetector according to claim 1, characterized in that: The thickness of the ReSe2 flakes is 1nm to 200nm.

5. The rhenium diselenide / black phosphorus arsenic heterojunction photodetector according to claim 1, characterized in that: The source electrode and the drain electrode are both one or a combination of multiple materials selected from Cr, Ti, Ni, Au, Pd, Pt or Ag, and the thickness of the source electrode and the drain electrode are both 50 nm to 80 nm.

6. The rhenium diselenide / black phosphorus arsenic heterojunction photodetector according to claim 5, characterized in that: The source and drain electrodes are both Cr / Au.

7. The method for preparing the rhenium diselenide / black phosphorus arsenic heterojunction photodetector according to any one of claims 1 to 6, characterized in that: The following steps are involved: 1) Ultrasonic cleaning of the rigid substrate using acetone, ethanol and deionized water in sequence, and drying; 2) Prepare AsP thin sheets and transfer them to rigid substrates; 3) Prepare ReSe2 flakes and transfer them to PDMS; 4) Directed transfer of multilayer ReSe2 sheets on PDMS to AsP sheets; 5) Define the electrode pattern and prepare the source electrode and drain electrode on the rigid substrate to form a ReSe2 / BPAs heterojunction photodetector.

8. The method for preparing the rhenium diselenide / black phosphorus arsenic heterojunction photodetector according to claim 7, characterized in that: In step 1, the ultrasonic cleaning time is 10 to 20 minutes.

9. The method for preparing the rhenium diselenide / black phosphorus arsenic heterojunction photodetector according to claim 7, characterized in that: In step 5, the electrode pattern is defined by using any method selected from ultraviolet photolithography, electron beam exposure or laser direct writing; the source electrode and the drain electrode are prepared by using any method selected from thermal evaporation, electron beam evaporation or magnetron sputtering and a lift-off method.

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