A photodetector based on two-dimensional topological insulator SnSb2Te4 thin film and its construction method

Abstract

The present invention discloses a photodetector based on a two-dimensional topological insulator SnSb2Te4 thin slice and a method for its construction. The two-dimensional SnSb2Te4 thin slice is transferred to a silicon / silicon dioxide substrate, and then source and drain electrodes are provided on the SnSb2Te4 thin slice to construct the photodetector. This photodetector features a simple structure, a wide response range, a fast response speed, and high stability, expanding the application of topological insulator materials in the field of photodetectors.

Description

Technical Field

[0001] The present invention belongs to the field of photoelectric detection of microelectronic semiconductor materials, and specifically relates to a photoelectric detector based on a two-dimensional topological insulator SnSb2Te4 thin slice and a construction method thereof. Background Art

[0002] Topological insulators are a new quantum state of matter discovered in recent years, exhibiting many novel physical properties. They possess a zero-bandgap surface state and a narrow-bandgap bulk state. The surface state connects the conduction and valence bands of the bulk state, enabling detection across a wide spectral range. Furthermore, carriers experience very low energy loss when moving in the surface state, resulting in high carrier mobility. Consequently, they hold great promise for the development of high-performance detectors. However, due to the relatively recent discovery of topological insulators, many challenges remain, such as the preparation of higher-quality topological insulator materials. Therefore, research on photodetectors based on topological insulators is still in its early stages. Therefore, the stable preparation of high-quality topological insulator materials and the investigation of their performance are crucial. Summary of the Invention

[0003] The present invention provides a two-dimensional topological insulator material, which is a SnSb2Te4 thin sheet.

[0004] According to an embodiment of the present invention, the SnSb2Te4 thin sheet is prepared on a substrate by chemical vapor deposition using antimony trichloride, tin tetrachloride and tellurium powder as raw materials. For example, the substrate is a fluorphlogopite mica sheet.

[0005] The present invention also provides a method for preparing the aforementioned SnSb2Te4 thin flakes, comprising the following steps: using antimony trichloride, tin tetrachloride or its hydrate, and tellurium powder as raw materials, and preparing the SnSb2Te4 thin flakes on a substrate by chemical vapor deposition. For example, the substrate is a fluorphlogopite mica sheet.

[0006] According to an embodiment of the present invention, the positional relationship of the antimony trichloride, tin tetrachloride, tellurium powder and substrate is as follows: antimony trichloride, tin tetrachloride, tellurium powder and substrate are arranged in order from near to far near the carrier gas inlet end.

[0007] According to an embodiment of the present invention, the preparation conditions of the chemical vapor deposition method include: a temperature of 550-600° C. and a time of 20-50 min; for example, a temperature of 550° C. and a time of 30 min.

[0008] According to an embodiment of the present invention, the carrier gas is hydrogen and argon.

[0009] According to an embodiment of the present invention, the method for preparing the SnSb2Te4 thin sheet comprises the following steps:

[0010] (1) preparing or preparing raw materials of antimony trichloride, tin tetrachloride or its hydrate, tellurium powder and fluorophlogopite mica flakes;

[0011] (2) placing the raw materials in a horizontal tube furnace, sealing it, and continuously drawing a vacuum;

[0012] (3) continuously introducing a carrier gas (e.g., 20 sccm of hydrogen, 100 sccm of argon) into the horizontal tube furnace and reacting at 550-600° C. for 20-50 min;

[0013] (4) After the reaction is completed, the mixture is cooled to room temperature to obtain the SnSb2Te4 thin sheets on fluorophlogopite.

[0014] The present invention also provides a photoelectric detector comprising the above-mentioned SnSb2Te4 thin slice.

[0015] According to an embodiment of the present invention, the photodetector includes a silicon / silicon dioxide substrate, the SnSb2Te4 thin sheet located on the silicon dioxide layer; and a source-drain electrode bonded to the SnSb2Te4 thin sheet.

[0016] According to an embodiment of the present invention, the thickness of the silicon dioxide layer is 200-400 nm, for example, 280 nm.

[0017] According to an embodiment of the present invention, the thickness of the SnSb2Te4 thin sheet is 20-80 nm, for example, 30 nm, 40 nm, 50 nm, 60 nm, or 70 nm.

[0018] According to an embodiment of the present invention, an electrode adhesion layer is provided between the SnSb2Te4 thin sheet and the source and drain electrodes.

[0019] According to an embodiment of the present invention, the source and drain electrodes are parallel electrodes running through the SnSb2Te4 thin sheet, and the spacing between the source and drain electrodes is preferably 2-30 μm, such as 4 μm, 5 μm, 10 μm, 15 μm, 20 μm, or 25 μm.

[0020] According to an embodiment of the present invention, the source and drain electrodes are titanium / gold electrodes. For example, the thickness of the titanium electrode is 5-10 nm, and the thickness of the gold electrode is 40-60 nm.

[0021] The present invention also provides a method for constructing the above-mentioned photodetector, comprising the following steps: transferring the SnSb2Te4 thin slice onto a silicon / silicon dioxide substrate, and then arranging source and drain electrodes on the SnSb2Te4 thin slice.

[0022] According to an embodiment of the present invention, the silicon / silicon dioxide substrate needs to be pretreated: the silicon / silicon dioxide substrate is ultrasonically treated with acetone, isopropyl alcohol and deionized water in sequence (eg, ultrasonically treated for 15 minutes), and then blown dry for use.

[0023] According to an embodiment of the present invention, the operation of transferring the SnSb2Te4 flakes to the silicon / silicon dioxide substrate includes: coating a PMMA (polymethyl methacrylate) film on the substrate containing the SnSb2Te4 flakes, the PMMA film completely covering the SnSb2Te4 flakes, baking and placing in water, separating the PMMA film with the SnSb2Te4 flakes adhered to it from the substrate, using a silicon / silicon dioxide substrate to receive the PMMA film with the SnSb2Te4 flakes adhered to it, heating, and soaking in an organic solvent, and transferring the SnSb2Te4 flakes to the silicon / silicon dioxide substrate;

[0024] Preferably, the substrate containing the SnSb2Te4 thin sheet is obtained by the above-mentioned method for preparing SnSb2Te4 thin sheets.

[0025] According to an embodiment of the present invention, the baking temperature is 90-110° C. and the baking time is 2-10 min; for example, baking at 100° C. for 5 min.

[0026] According to an embodiment of the present invention, the heating temperature is 90-110° C. and the heating time is 2-10 min; for example, baking at 100° C. for 5 min.

[0027] According to an embodiment of the present invention, the organic solvent is selected from solvents that can dissolve the PMMA film but do not affect the SnSb2Te4 flakes, such as acetone.

[0028] According to an embodiment of the present invention, the source-drain electrodes may be prepared by an electron beam evaporation deposition method.

[0029] According to an embodiment of the present invention, the method for constructing the photodetector comprises the following steps:

[0030] (1) Cutting and cleaning the silicon / silicon dioxide substrate, ultrasonically cleaning with acetone, isopropyl alcohol, and deionized water in sequence, and drying with nitrogen for later use;

[0031] (2) coating a PMMA film on the substrate containing the SnSb2Te4 flakes, the PMMA film completely covering the SnSb2Te4 flakes, baking and placing in water, separating the PMMA film with the SnSb2Te4 flakes adhered thereto from the substrate, placing the PMMA film with the SnSb2Te4 flakes adhered thereto on a silicon / silicon dioxide substrate, heating and soaking in an organic solvent, and transferring the SnSb2Te4 flakes to the silicon / silicon dioxide substrate;

[0032] (3) After step (2) is completed, glue is applied on the SnSb2Te4 thin sheet, and titanium / gold electrodes are deposited by electron beam evaporation to obtain parallel electrodes that penetrate the SnSb2Te4 thin sheet.

[0033] Preferably, the rotation speed of the glue coating in step (3) includes a low speed of 800 r / min and a high speed of 2000-4000 r / min.

[0034] Beneficial effects

[0035] (1) The present invention provides two-dimensional SnSb2Te4 thin sheets, which are grown using a chemical vapor deposition method. This method can stably grow two-dimensional SnSb2Te4 thin sheets with good quality. The two-dimensional SnSb2Te4 thin sheets are suitable for ultrafast photoelectric sensor applications, expanding the application of topological insulator materials in photodetectors.

[0036] (2) The photodetector constructed based on two-dimensional SnSb2Te4 thin sheets has a wide response range, from the visible to the near-infrared range, and has a fast response speed and good response stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Schematic diagram of chemical vapor deposition growth.

[0038] Figure 2 Schematic diagram of a two-dimensional topological insulator SnSb2Te4 thin film photodetector.

[0039] Figure 3 This is a picture of the two-dimensional topological insulator SnSb2Te4 thin film under a scanning electron microscope.

[0040] Figure 4 This is the XRD analysis diagram of the two-dimensional topological insulator SnSb2Te4 thin film.

[0041] Figure 5 IT curves at different wavelengths of the photodetector based on the two-dimensional topological insulator SnSb2Te4 thin film.

[0042] Figure 6 This is the IT curve of the photodetector based on the two-dimensional topological insulator SnSb2Te4 thin film at a wavelength of 488nm. DETAILED DESCRIPTION

[0043] The technical solutions of the present invention will be described in further detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are encompassed within the scope of protection that the present invention is intended to protect.

[0044] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0045] Example 1

[0046] Two-dimensional topological insulator SnSb2Te4 thin sheets and their growth methods:

[0047] Use a precision balance to weigh 0.456g of antimony trichloride, 0.350g of tin tetrachloride pentahydrate, and 0.508g of tellurium powder. Prepare a piece of fluorphlogopite mica and place the raw materials in a quartz boat. Figure 2 The positions shown are: antimony trichloride, tin tetrachloride pentahydrate, tellurium powder, and fluorphlogopite mica sheets, from near to far, near the carrier gas inlet. Place them in a tube furnace. Seal the tube furnace and continuously evacuate it. Continuously introduce 20 sccm of hydrogen and 100 sccm of argon into the tube furnace. Heat the temperature from room temperature to 550 degrees Celsius over 20 minutes, maintain it at 550 degrees Celsius for 30 minutes, and then cool it naturally to room temperature. Figure 4 The XRD characterization shown in the figure shows that two-dimensional SnSb2Te4 thin sheets were successfully obtained on fluorphlogopite mica sheets. The morphology of SnSb2Te4 thin sheets is as follows Figure 3 As shown, its thickness ranges from 20 to 80 nm.

[0048] Example 2

[0049] Photodetector based on two-dimensional topological insulator SnSb2Te4 thin film and its preparation method:

[0050] Step 1: Wet transfer of two-dimensional topological insulator SnSb2Te4 thin sheets. The specific steps are as follows: first, cut the silicon wafer with the silicon dioxide oxide layer into 1cm×1cm size, then sequentially ultrasonicate with acetone, isopropanol and deionized water for 15 minutes each, blow dry with nitrogen and set aside for use, spin-coat a layer of PMMA (polymethyl methacrylate) on the fluorphlogopite mica sheet containing SnSb2Te4 thin sheets prepared in Example 1, place it on a 100-degree Celsius constant temperature table and bake it for 5 minutes, then slowly immerse the fluorphlogopite mica sheet in a container filled with deionized water, wait for the PMMA film to separate from the mica substrate, and then use the prepared silicon wafer to slowly pick up the PMMA film containing SnSb2Te4 thin sheets from the bottom, heat it at 100 degrees Celsius for 5 minutes, then place it in an acetone solution for 30 minutes, remove the PMMA film, and blow dry it with a nitrogen gun to obtain a two-dimensional SnSb2Te4 thin sheet on the silicon wafer.

[0051] Step 2: Arrange titanium / gold metal electrodes on the SnSb2Te4 wafer. Specifically, use a spin coater to evenly spin-coat a layer of methyl methacrylate (MMA) onto the SnSb2Te4 wafer on the silicon wafer. After heating on a heating table for 3 minutes, a layer of polymethyl methacrylate (PMMA) is evenly spin-coated onto the SnSb2Te4 wafer on the silicon wafer. The spin coater operates at a low speed of 800 rpm and a high speed of 4000 rpm, for 10 seconds and 50 seconds, respectively. After the spin coat is completed, the sample is denatured using electron beam exposure. The exposed sample is placed in a developer for 30 seconds to develop the parallel electrodes. After development, it is rinsed with deionized water and then dried. Electron beam evaporation is used to deposit 10 nm and 50 nm of titanium / gold, respectively. After deposition, the glue is etched with acetone to reveal the parallel electrodes that extend through the SnSb2Te4 wafer. This completes the photodetector device fabrication process.

[0052] The structure of photodetector device is as follows Figure 1 As shown, it includes a silicon / silicon dioxide substrate, a SnSb2Te4 thin sheet located on the silicon dioxide layer; and a source and drain electrode bonded to the SnSb2Te4 thin sheet.

[0053] Figure 5 as well as Figure 6 Photoelectric test curve of the photodetector based on the two-dimensional topological insulator SnSb2Te4 thin film. Figure 5 The current change curve of the photodetector under different laser wavelengths shows that the photodetector has a stable light response at wavelengths of 488-1550nm. Figure 6 The photoelectric test IT curve of SnSb2Te4 photodetector with light source on and off is shown in Figure 2. When the light is on, the current increases and gradually returns to a stable state. When the light is off, the current decreases and tends to be stable. 2 When irradiated by 488nm infrared laser, the light response time is about 60 microseconds.

[0054] The above description shows that the photodetector prepared based on two-dimensional SnSb2Te4 thin sheets has the advantages of wide response range, ultrafast response speed, good stability, etc., which is suitable for ultrafast photoelectric sensor applications and expands the application of topological insulator materials in photodetectors.

[0055] The above describes the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A two-dimensional topological insulator material, characterized in that The two-dimensional topological insulator material is a SnSb2Te4 thin sheet; the SnSb2Te4 thin sheet is prepared on a substrate by chemical vapor deposition using antimony trichloride, tin tetrachloride and tellurium powder as raw materials; The thickness of the SnSb2Te4 flakes is 20-80 nm.

2. The method for preparing SnSb2Te4 thin sheets according to claim 1, characterized in that: The preparation method comprises the following steps: using antimony trichloride, tin tetrachloride or its hydrate, and tellurium powder as raw materials, and preparing the SnSb2Te4 thin slice on a substrate by chemical vapor deposition.

3. The preparation method according to claim 2, characterized in that The positional relationship of the antimony trichloride, tin tetrachloride, tellurium powder and substrate is as follows: antimony trichloride, tin tetrachloride, tellurium powder and substrate are located in the order from near to far near the carrier gas inlet end.

4. A photoelectric detector, characterized in that: The photodetector comprises the SnSb2Te4 thin sheet according to claim 1.

5. The photodetector according to claim 4, wherein: The photodetector includes a silicon / silicon dioxide substrate, the SnSb2Te4 thin slice located on the silicon dioxide layer; and a source-drain electrode bonded to the SnSb2Te4 thin slice.

6. The photodetector according to claim 5, wherein: The thickness of the silicon dioxide layer is 200-400 nm; and / or, an electrode adhesion layer is provided between the SnSb2Te4 thin sheet and the source and drain electrodes; and / or, the source and drain electrodes are parallel electrodes that penetrate the SnSb2Te4 thin sheet; And / or, the source / drain electrodes are titanium / gold electrodes.

7. The photodetector according to claim 6, wherein: The distance between the source and drain electrodes is 2-30 μm.

8. The method for constructing a photodetector according to any one of claims 5 to 7, characterized in that: The construction method includes the following steps: transferring the SnSb2Te4 thin slice onto a silicon / silicon dioxide substrate, and then arranging source and drain electrodes on the SnSb2Te4 thin slice.

9. The construction method according to claim 8, characterized in that: The silicon / silicon dioxide substrate needs to be pretreated: the silicon / silicon dioxide substrate is ultrasonically treated with acetone, isopropyl alcohol and deionized water in sequence, and then blown dry for later use.

10. The construction method according to claim 8 or 9, characterized in that: The operation of transferring the SnSb2Te4 flakes to the silicon / silicon dioxide substrate includes: coating a PMMA film completely covering the SnSb2Te4 flakes on the substrate containing the SnSb2Te4 flakes, baking the film, and placing the film in water; separating the PMMA film with the SnSb2Te4 flakes adhered thereto from the substrate; placing the PMMA film with the SnSb2Te4 flakes adhered thereto on a silicon / silicon dioxide substrate; heating the film, and soaking the film in an organic solvent; and transferring the SnSb2Te4 flakes to the silicon / silicon dioxide substrate. The organic solvent is selected from solvents that can dissolve the PMMA film but do not affect the SnSb2Te4 flakes.

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