Preparation method of silicon-based photoelectric detector with infrared band photoelectric detection function

Abstract

The present invention discloses a method for preparing a silicon-based photodetector with an infrared band photoelectric detection function, which comprises: performing surface oxidation treatment on silicon nanopowder to obtain silicon / silicon oxide core-shell nanopowder, using silicon / silicon oxide core-shell nanopowder as a photosensitive material to construct a silicon-based photodetector, applying external pressure to the silicon / silicon oxide core-shell nanopowder, and the photoelectric detection performance of the silicon-based photodetector changes with the change of pressure, and the silicon-based photodetector has an infrared band photoelectric detection function under the action of pressure. The method of the present invention has low cost and high efficiency, and provides a new idea for designing a new type of high-efficiency silicon-based photodetector.

Description

Technical Field

[0001] The invention belongs to the field of infrared detection photoelectric technology, and specifically relates to a method for preparing a novel silicon-based photoelectric detector with infrared band photoelectric detection function. Background Art

[0002] Detectors made of semiconductor materials have gradually become the main "carrier" for detecting light due to their advantages of high performance, low energy consumption, wide detection range, durability, and small size and lightness. Infrared detection technology plays an important role in both civilian and military fields. In civilian applications, it is widely used in security monitoring, fire warning, medical diagnosis, and industrial production, providing a safer and more convenient environment for people's lives and work. In the military field, infrared detection technology is used in key areas such as night vision equipment, missile guidance systems, and intelligence reconnaissance, providing the military with battlefield perception and combat advantages. With the continuous development of science and technology, infrared detection technology will continue to play an important role in promoting the development and progress of various fields.

[0003] Infrared detection technology is based on pyroelectric, photoelectric and thermo-optical principles. Currently, detectors are mainly made of materials such as III-V compound semiconductors (such as InGaAs, InGaAsP, IGaAlAs) and germanium, which have good photoelectric properties in the infrared band. However, these materials are expensive and incompatible with common silicon-based semiconductors, with high manufacturing costs and great technical difficulty.

[0004] As one of the earliest discovered semiconductor materials, silicon has been the most used semiconductor material since its introduction, with a market share of 97.2%. With its unique advantages such as abundant resources, easy production, and easy doping, it has always been the first choice for preparing photodetectors. Silicon-based infrared detection technology is one of the current research hotspots. The detection performance of silicon materials in the infrared band is poor, and its bandgap width is 1.12ev at room temperature, so it cannot respond to infrared light exceeding 1100nm, which greatly restricts the detection application of silicon materials in the infrared band. In order to expand the infrared detection range of silicon, researchers have proposed a new method, which is to enhance the infrared detection performance of silicon-based materials by growing doped silicon films outward. However, this method has problems such as low efficiency, limited optical properties, lattice mismatch with the silicon substrate, and mismatch in thermal expansion coefficient, which affects the performance and stability of the detector in a specific infrared band. Therefore, researchers are constantly exploring other technologies to solve the problems currently faced by infrared detectors. Summary of the invention

[0005] The present invention aims to solve the deficiencies of the above-mentioned prior art and proposes a method for preparing a silicon-based photoelectric detector with infrared band photoelectric detection function, that is, a method for regulating the infrared band photoelectric detection performance of the silicon-based photoelectric detector.

[0006] In order to achieve the above object, the present invention adopts the following technical scheme:

[0007] The present invention first provides a method for preparing a silicon-based photoelectric detector with infrared band photoelectric detection function, which is characterized in that: silicon nanopowder is subjected to surface oxidation treatment to obtain silicon / silicon oxide core-shell nanopowder, silicon / silicon oxide core-shell nanopowder is used as a photosensitive material to construct a silicon-based photoelectric detector, external pressure is applied to the silicon / silicon oxide core-shell nanopowder, the photoelectric detection performance of the silicon-based photoelectric detector changes with the change of pressure, and the silicon-based photoelectric detector has infrared band photoelectric detection function under the action of pressure.

[0008] Furthermore, the step of surface oxidation treatment is: placing the silicon nanopowder on a heating table and annealing at 200-500° C. for 3-12 hours in an air atmosphere.

[0009] Further, a diamond anvil cell is used to apply external pressure to the silicon / silicon oxide core-shell nanopowder, and the specific method is as follows:

[0010] First, assemble the diamond anvils: take a pair of diamond anvils and bases and clean them ultrasonically; use a 304 stainless steel sheet with an insulation treatment on the surface as a gasket, punch a hole in the middle to form a sample cavity, and the inner wall of the sample cavity has an insulation layer; during assembly, place the two diamond anvil surfaces opposite each other up and down, sandwich a gasket in the middle and make the center of the sample cavity coincide with the center of the diamond anvil surface; put silicon / silicon oxide core-shell nanopowder into the sample cavity, then place two platinum electrodes on the silicon / silicon oxide core-shell nanopowder, and lead the two platinum electrodes out of the sample cavity and connect them to copper wires; then place ruby ​​powder in the sample cavity for pressure calibration;

[0011] Then, the pressure was applied: the diamond anvil was pressurized and the pressure was calibrated using a ruby ​​pressure gauge system; after the pressure was calibrated, the copper wire was connected to the electrical measurement equipment, and voltage was applied to the sample in a dark environment to obtain an IV curve; then an infrared laser was used to irradiate the silicon / silicon oxide core-shell nanopowder to obtain a curve of the relationship between the photocurrent and time. As the pressure increased, the IV curve of the silicon / silicon oxide core-shell nanopowder changed linearly, and the light response of the silicon / silicon oxide core-shell nanopowder in the infrared band was enhanced.

[0012] Furthermore, the infrared band laser is a near-infrared to mid-infrared (0.75~4μm) band laser.

[0013] Furthermore, the insulating layer of the inner side wall of the sample cavity is formed by filling the sample cavity with boron nitride insulating powder and applying pressure.

[0014] Based on the above method, the present invention also provides a silicon-based photoelectric detector with infrared band photoelectric detection function, which is constructed by silicon nanopowder that has been surface-oxidized according to the above method and has external pressure applied.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The present invention proposes a method for preparing a silicon-based photoelectric detector with infrared band photoelectric detection function. The infrared band photoelectric detection performance of the silicon-based photoelectric detector is regulated by surface oxidation treatment and applying external pressure, so that the silicon nanopowder has the infrared band photoelectric detection function. In the process of gradually increasing pressure, the photocurrent of the silicon / silicon oxide core-shell structure nanopowder excited by infrared light increases significantly, which improves the photoelectric detection performance of the silicon-based photoelectric detector in the infrared band, and provides a new direction for the application of silicon in the field of infrared band photoelectric detection manufacturing technology. The method of the present invention has low cost and high efficiency, and provides a new idea for designing new high-efficiency silicon-based photoelectric detectors. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The figure is a schematic diagram of the preparation process of the silicon-based photoelectric detector with infrared band photoelectric detection function of the present invention;

[0018] Figure 2 This is an XPS graph of silicon / silicon oxide core-shell nanopowder obtained after annealing the silicon nanopowder in Example 1 of the present invention;

[0019] Figure 3 This is a schematic diagram of the diamond anvil after assembly in Example 1 of the present invention;

[0020] Figure 4 This is a schematic diagram of the electrode construction in the sample chamber in Example 1 of the present invention;

[0021] Figure 5 The IV curves of the samples in Example 1 of the present invention at different pressures;

[0022] Figure 6 The photocurrent variation curve of silicon / silicon oxide core-shell nanopowder irradiated with 1550nm laser at different pressures in Example 1 of the present invention over time;

[0023] Explanation of reference numerals: 1 - sample chamber; 2 - platinum electrode; 3 - copper wire; 4 - diamond anvil surface; 5 - 304 stainless steel gasket; 6 - diamond anvil; 7 - electrical measurement equipment. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Those skilled in the art should know that the embodiments described below are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0025] Example 1

[0026] To verify the feasibility of the present invention, this embodiment takes silicon nanopowder as an example to regulate its photoelectric properties in the near-infrared band. The specific steps are as follows:

[0027] Step 1. Surface oxidation treatment of silicon nanopowder

[0028] The silicon nanopowder was placed on a heating table and annealed at 300°C for 5 hours in an air atmosphere to obtain silicon / silicon oxide core-shell nanopowder. The XPS of the annealed sample was measured to obtain the silicon and oxygen composition ratio. Figure 2 As shown, the silicon content of the silicon / silicon oxide core-shell nanopowder obtained after annealing the silicon nanopowder is 87.45%, and the oxygen content is 11.56%.

[0029] Step 2. Prepare the diamond anvil

[0030] Ultrasonic clean a pair of 500μm table diamond anvils and bases; place the diamond anvil in the center of the base for the first step of alignment; take black glue and black glue catalyst, mix them evenly in a mass ratio of 93:7, and then apply them to the aligned diamond anvil and base, adhere the two, and dry them for 24 hours; place one of the bonded diamond anvils and bases in the piston for the second step of alignment; place the other bonded anvil and base in the cylinder, close the press, and perform the third step of alignment.

[0031] Step 3. Make the sample cavity and do insulation

[0032] Select 304 stainless steel sheet as gasket, use diamond anvil to pre-press and leave indentation on the steel sheet, use laser drilling device to drill hole at concentric circle of gasket indentation center, hole diameter is 500μm; fill the hole with boron nitride insulation powder and pressurize, then drill hole again at the place filled with insulation powder, hole diameter is 300μm, to form insulation sample cavity. Apply black glue to the outside of gasket hole for insulation treatment and let dry.

[0033] Step 4. Place silicon / silicon oxide core-shell nanopowder into the diamond anvil cell sample chamber and build electrodes in the sample chamber.

[0034] First, fix the thin copper wire on the insulated gasket; then place the silicon / silicon oxide core-shell nanopowder in the sample cavity, and place ruby ​​powder; cut two platinum sheets with a width of 30-50 μm and a thickness of 4 μm, place one end of the platinum sheet in the sample cavity to contact the silicon / silicon oxide core-shell nanopowder, and the other end to contact and fix the thin copper wire. The two platinum sheets do not touch each other in the sample cavity; apply silver glue to the connection between the platinum sheet and the thin copper wire to fix them, and ensure that there is a passage between the two, and let them dry. The diamond anvil after assembling and building the electrode is as follows Figure 3 and Figure 4 shown.

[0035] Step 5. Pressurize and measure the sample chamber pressure using the ruby ​​pressure method

[0036] Close the press, lead out the copper wire, and use a hexagonal pressure wrench to pressurize the diamond anvil; use a ruby ​​pressure calibration system to calibrate the pressure, and select a 532nm laser.

[0037] Step 6. Apply voltage across the sample, use electrical measurement equipment to collect loop current and draw an IV curve

[0038] After pressure calibration, the derived copper wire leads were connected to an electrical measurement device (source meter), and voltage was applied to the sample in a dark environment to obtain IV curves at different pressures.

[0039] Step 7. Use a near-infrared laser with a wavelength of 1550nm to irradiate the silicon / silicon oxide core-shell nanopowder and obtain a curve of the relationship between the photocurrent and time.

[0040] Place the diamond anvil press on an optical platform, and then connect the lead-out copper wire to the electrical measuring equipment; turn on the power, first measure the dark current of the silicon / silicon oxide core-shell nanopowder for 50 seconds; then irradiate the diamond anvil sample cavity with a laser with a wavelength of 1550nm for 50 seconds and collect its photocurrent; one cycle is 100 seconds, and repeated 4-5 times to obtain the relationship curve between the photocurrent and time of the silicon / silicon oxide core-shell nanopowder irradiated with 1550nm laser under different pressures.

[0041] like Figure 5 As shown, when the pressures are 2.8 GPa, 3.4 GPa, 4.6 GPa, 5.5 GPa, and 6.5 GPa, respectively, the IV curves of silicon / silicon oxide core-shell nanopowders in a dark environment change linearly.

[0042] like Figure 6As shown, when the pressure is 2.8 GPa, 3.4 GPa, 4.6 GPa, 5.5 GPa and 6.5 GPa respectively, using a laser with a wavelength of 1550 nm as the light source, as the pressure increases, the photocurrent increases by an order of magnitude compared with normal pressure, indicating that the pressure increases the light response of silicon / silicon oxide nanopowder in the near-infrared band and the photoelectric performance of the material is improved.

[0043] Based on this method, the photoelectric performance of silicon nanopowder has been significantly improved with the increase of pressure. This method has great application prospects in the field of near-infrared photoelectric detection of silicon-based photodetectors in the future.

[0044] The above is only a preferred experimental scheme of the present invention. For technicians in this technical field, without departing from the design concept of the present invention, they can also make several improvements such as material replacement (such as amorphous silicon, silicon PN junction, heterojunction and other silicon-based photodetectors), parameter changes (such as pressure size, measurement voltage, light source wavelength and intensity, etc.), etc., and these improvements should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a silicon-based photodetector having infrared band photodetection function, characterized in that: After surface oxidation treatment of silicon nanopowder, silicon / silicon oxide core-shell nanopowder is obtained. The surface oxidation treatment comprises the following steps: placing silicon nanopowder on a heating table, annealing at 200-500° C. for 3-12 hours in an air atmosphere, wherein the silicon content of the silicon / silicon oxide core-shell nanopowder obtained after annealing the silicon nanopowder is 87.45%, and the oxygen content is 11.56%. A silicon-based photodetector is constructed using the silicon / silicon oxide core-shell nanopowder as a photosensitive material, and external pressure is applied to the silicon / silicon oxide core-shell nanopowder. The photoelectric detection performance of the silicon-based photodetector changes with the change of pressure, and the silicon-based photodetector has an infrared band photoelectric detection function under the action of pressure. The infrared band is a near-infrared to mid-infrared band laser, and the wavelength of the infrared band laser is 1550 nm. Applying external pressure to the silicon / silicon oxide core-shell nanopowder using a diamond anvil cell; First, assemble the diamond anvils: take a pair of diamond anvils and bases and clean them ultrasonically; use a 304 stainless steel sheet with an insulation treatment on the surface as a gasket, punch a hole in the middle to form a sample cavity, and the inner wall of the sample cavity has an insulation layer; during assembly, place the two diamond anvil surfaces opposite each other up and down, sandwich a gasket in the middle and make the center of the sample cavity coincide with the center of the diamond anvil surface; put silicon / silicon oxide core-shell nanopowder into the sample cavity, then place two platinum electrodes on the silicon / silicon oxide core-shell nanopowder, and lead the two platinum electrodes out of the sample cavity and connect them to copper wires; then place ruby ​​powder in the sample cavity for pressure calibration; Then pressurize: pressurize the diamond anvil and calibrate the pressure using a ruby ​​pressure gauge system; After pressure calibration, the copper wire is connected to the electrical measuring equipment, and voltage is applied to the sample in a dark environment to obtain the IV curve; then an infrared laser is used to irradiate the silicon / silicon oxide core-shell nanopowder to obtain a curve of the relationship between photocurrent and time.

2. The method for preparing a silicon-based photoelectric detector having an infrared band photoelectric detection function according to claim 1, characterized in that: With the increase of pressure, the IV curve of silicon / silicon oxide core-shell nanopowder changes linearly, and the optical response of silicon / silicon oxide core-shell nanopowder in the infrared band is enhanced.

3. The method for preparing a silicon-based photoelectric detector having an infrared band photoelectric detection function according to claim 2, characterized in that: The insulating layer of the inner wall of the sample cavity is formed by filling the sample cavity with boron nitride insulating powder and applying pressure.

4. A silicon-based photodetector with infrared band photodetection function, characterized in that: The invention is constructed by silicon nanopowder which is subjected to surface oxidation treatment according to the method described in any one of claims 1 to 3 and to which external pressure is applied.

Images