Broadband self-driven photoelectric detector based on 2D Sb2O3 / PdTe2 / Si heterojunction and preparation method thereof

Abstract

The invention belongs to the technical field of optical detection, and particularly relates to a broadband self-driven photoelectric detector which sequentially comprises a metal In point electrode, a metal Pd front electrode, a PdTe2 modified Sb2O3 two-dimensional thin film layer, a Si single crystal substrate and a metal In back electrode from top to bottom. The Sb2O3 two-dimensional thin film layer prepared through modification of PdTe2 is prepared through magnetron sputtering, chemical vapor deposition and other methods. Test results show that the prepared thin film device shows good self-driven light detection performance under illumination from deep ultraviolet to infrared light, and has the advantages of stable performance and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of light detection, and in particular relates to a broadband self-driven photoelectric detector and a preparation method thereof. Background Art

[0002] Photodetectors are electronic devices that can convert light signals into electrical signals. Photodetectors have been widely used in biological imaging, nondestructive testing, communications, environmental monitoring and other fields. However, most of the photodetectors reported so far can only achieve single-band detection, so the development and improvement of broadband photodetectors is particularly important.

[0003] Broadband photoelectric detection technology is a new technology that can convert optical signals with different wavelengths into electrical signals. It can complete broadband light detection from ultraviolet light to infrared light, and achieve a detection bandwidth that can only be achieved when multiple detectors work simultaneously. It has extremely important application value in space science, marine fisheries, resource surveys, environmental monitoring, military, communications, etc. One of the core units of broadband photoelectric detection technology is the photoelectric detection material, which is an important factor in determining the performance and price of broadband photoelectric detector devices. Therefore, the development of new photoelectric detection materials has extremely important scientific significance and application value.

[0004] The sensitivity of photosensitive materials is often related to their ability to absorb light of a specific wavelength, which requires a trade-off between sensitivity and wavelength range when designing broadband photodetectors to ensure that the desired light signal can be effectively captured. Metal oxide semiconductors are ideal for sensitive materials in optoelectronic devices due to their special electronic and optoelectronic properties. Their low-dimensional nanostructures have large band gaps and good conductivity. They have broad prospects for large-scale assembly of high-performance photodetectors because of their stable nanostructures and easy preparation and processing. In addition, Si is compatible with complementary metal oxide semiconductor processes, so metal oxide / Si heterojunctions are widely used in the field of light detection.

[0005] The main features of an excellent photodetector are high responsivity, excellent detection, long-term stability and low manufacturing cost. As a two-dimensional (2D) inorganic molecular van der Waals crystal, Sb2O3 is widely regarded as an excellent dielectric and packaging material due to its wide bandgap (≈4eV), high dielectric constant and extremely high air stability. It has been used in the development of semiconductor materials. The corresponding light absorption band edge is ultraviolet light, which is a very promising wide bandgap material. Therefore, exploring how to prepare two-dimensional Sb2O3 thin films on Si substrates is the first problem we need to solve. However, due to the uncertainty of the epitaxial growth direction of Sb on the silicon (Si) surface, the Sb-based materials formed on silicon have directional differences and easy agglomeration problems. To address these problems, we took advantage of the hexagonal symmetry of the transition metal chalcogenide PdTe2 and the matching of its lattice period with the periodic lattice in the Sb single crystal layer to optimize the growth morphology of the Sb-based material, construct a mixed dimensional heterojunction, and greatly improve the performance of the device. At the same time, the light absorption range of Sb2O3 was widened to infrared, and a Sb2O3-based broadband photodetector was successfully constructed. Summary of the invention

[0006] The purpose of the present invention is to provide a broadband self-driven electrical detector based on 2D Sb2O3 / PdTe2 / Si heterojunction and a preparation method thereof, which can further broaden the detection range of the current broadband photoelectric detector and improve its photoelectric performance.

[0007] The technical problem to be solved by the present invention to achieve the above-mentioned purpose is to improve the performance of the photodetector by methods such as magnetron sputtering and chemical vapor deposition; that is, a PdTe2-modified Sb2O3 two-dimensional thin film layer is prepared on the surface of a silicon substrate by magnetron sputtering and chemical vapor deposition methods to obtain a self-driven photodetector with excellent wide-band detection.

[0008] The technical solution adopted by the present invention to achieve the above-mentioned purpose is a broadband self-driven electrical detector based on a 2D Sb2O3 / PdTe2 / Si heterojunction, characterized in that it is a layered structure, which includes, from top to bottom, a metal In point electrode, a metal Pd front electrode, a Sb2O3 two-dimensional thin film layer modified and grown by PdTe2, a Si single crystal substrate and a metal In back electrode; wherein:

[0009] Preferably, the Si single crystal substrate is single-sided polished, has a crystal plane orientation of (100), is p-type conductive, and has a resistivity of 0.1 to 1 ohm·cm;

[0010] A method for preparing a broadband self-driven electrical detector based on a 2D Sb2O3 / PdTe2 / Si heterojunction comprises the following steps:

[0011] (1) Selecting a Si substrate and cleaning it;

[0012] (2) Drying the cleaned Si substrate;

[0013] (3) placing the dried Si substrate into a vacuum chamber, and using radio frequency magnetron sputtering technology in an argon environment to bombard a Pd target with ionized argon ions to deposit a Pd thin film layer on the surface of the Si substrate; the target purity is 99.9%, the argon pressure is maintained at 1.2 Pascals, the target-substrate distance is 50 mm, the deposition temperature of the film is 20-25 degrees Celsius, and the film thickness is 10-20 nanometers;

[0014] (4) Place a Si substrate covered with a Pd thin film layer into the back end of CVD, add Te powder to the front end, set the evaporation temperature to 430°C, set the back end reaction temperature to 480°C, introduce gas, and increase the temperature at a rate of 5°C per minute. Maintain the temperature at 480°C for 150 minutes, and then cool naturally to room temperature to obtain a PdTe2 substrate on Si.

[0015] (5) The Si substrate with the PdTe2 substrate is placed in the back end of the CVD, Sb powder is added to the front end, the evaporation temperature is 400°C, the reaction temperature at the back end is 100°C, and the gas is introduced. During the reaction, the pressure in the tube is always maintained at 1Pa, and the temperature rise rate is 5 degrees Celsius per minute. After reaching the set temperature, it is kept warm for 30 minutes and then naturally cooled to room temperature; a Sb2O3 two-dimensional film is obtained on the PdTe2 substrate.

[0016] (6) taking out the sample obtained in step (5), covering the surface of the Sb2O3 two-dimensional thin film layer grown on the PdTe2 surface with a mask, and then placing the sample in a vacuum chamber; using a DC magnetron sputtering technique, bombarding a metal Pd target with ionized argon ions, and depositing a metal Pd front electrode on the surface of the Sb2O3 two-dimensional thin film layer grown on the PdTe2 surface; the Pd target is a Pd metal target, and the purity of the target is 99.9%; the argon gas pressure is maintained at 5.0 Pascals, the target-substrate distance is 50 mm, the deposition temperature of the metal Pd film is 20 to 25 degrees Celsius, and the thickness of the metal Pd front electrode is 5 to 15 nanometers;

[0017] (7) The metal In electrode is pressed onto the metal Pd front electrode and the Si substrate respectively, and the metal Cu wire is led out to complete the preparation of the device.

[0018] Preferably, in step (1), the Si substrate is a p-type Si single crystal substrate with a size of 10 mm×10 mm and a resistivity of 0.1 to 1 ohm·cm; the cleaning process is as follows: the Si substrate is ultrasonically cleaned in high-purity alcohol and acetone solutions for multiple times, each cleaning time being 20 minutes.

[0019] Preferably, in step (3), the back vacuum degree of the vacuum chamber is 5×10 -5 Pascal, vacuum conditions are produced by a two-stage vacuum pump consisting of a mechanical pump and a molecular pump.

[0020] Preferably, in step (4), the gases introduced are argon and hydrogen, the argon flow rate is 45 sccm, and the hydrogen flow rate is 5 sccm.

[0021] Preferably, in step (5), the gases introduced are argon and oxygen, the argon flow rate is 45 sccm, and the oxygen flow rate is 5 sccm.

[0022] Preferably, in step (6), the mask sheet is made of stainless steel, has a thickness of 0.1 mm, a size of 12 mm×12 mm, and an aperture size of 5 mm×5 mm; the back vacuum degree of the vacuum chamber is 5×10 -5 Pascal, vacuum conditions are produced by a two-stage vacuum pump consisting of a mechanical pump and a molecular pump.

[0023] Preferably, in step (7), the metal electrode and wire materials are In and Cu, respectively, wherein the purity of In is 99.5%, the size and thickness of the metal In electrode on the metal Pd thin film layer are 1 mm×1.5 mm and 1 mm, respectively, the size and thickness of the metal In electrode on the Si substrate are 10 mm×10 mm and 2 mm, respectively, and the diameter of the Cu wire is 0.1 mm.

[0024] The device having broadband self-driven light detection capability can be used in the preparation of broadband self-driven photodetectors.

[0025] The beneficial technical effects of the present invention are:

[0026] The invention prepares a two-dimensional Sb2O3 thin film layer on the surface of a Si substrate using PdTe2 modification, and develops a thin film device with broadband self-driven light detection capability. The test results show that the prepared thin film device has obvious sensitivity to light from deep ultraviolet to infrared. When the operating voltage is 0 volts, the device current increases significantly under light conditions. A broadband self-driven photodetector is successfully prepared, and the response of the prepared thin film device to light increases with the increase of light intensity. At the same time, the device has the advantages of good periodic repeatability. Compared with the existing broadband photodetectors, the preparation method of the device involved in the present invention is simple, non-toxic, low-cost, and has the advantages of significant ultra-wideband light response performance, and can be widely used in the field of photodetectors. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is the XRD characterization diagram of the prepared device.

[0028] Figure 2Schematic diagram of the structure for measuring the light detection performance of the prepared device.

[0029] Figure 3 The response performance of the device to deep ultraviolet light of different powers when the external voltage is 0 volt.

[0030] Figure 4 This is the SEM characterization image of Sb2O3 two-dimensional thin film.

[0031] Figure 5 This is the SEM characterization image of PdTe2.

[0032] Figure 6 This is the SEM characterization image of Sb2O3 two-dimensional thin film grown on PdTe2 surface. DETAILED DESCRIPTION

[0033] The present invention uses magnetron sputtering, chemical vapor deposition and other methods to prepare a Sb2O3 two-dimensional thin film layer on a Si semiconductor substrate using PdTe2 modification, deposits a metal Pd front electrode by DC magnetron sputtering technology, and presses a metal In electrode and connects a metal wire to form a device. When exposed to light conditions, due to the photoelectric effect and the existence of a built-in electric field, the device can still show obvious response performance when the applied voltage is 0 volts, and the photoelectric measurement band can range from deep ultraviolet to infrared.

[0034] The present invention is described in detail below in conjunction with the embodiments and drawings.

[0035] The invention discloses a broadband self-driven electric detector based on a 2D Sb2O3 / PdTe2 / Si heterojunction, comprising a Sb2O3 two-dimensional thin film layer prepared by modifying PdTe2 and a Si semiconductor substrate, wherein the Si substrate is used as a carrier of PdTe2, and the Sb2O3 two-dimensional thin film layer prepared by modifying PdTe2 is arranged on the surface of the Si substrate. The Si substrate is a p-type Si single crystal substrate, has a resistivity of 0.1 to 1 ohm·cm, and a crystal orientation of (100).

[0036] Further, the surface of the Sb2O3 two-dimensional thin film layer grown on the surface of PdTe2 is covered with a mask sheet, and then the sample is placed in a vacuum chamber; DC magnetron sputtering technology is used to bombard the metal Pd target with ionized argon ions, and a metal Pd front electrode is deposited on the surface of the Sb2O3 two-dimensional thin film layer grown on the surface of PdTe2; the Pd target is a Pd metal target, and the target purity is 99.9%; the argon gas pressure is maintained at 5.0 Pascals, the target-substrate distance is 50 mm, the deposition temperature of the metal Pd film is 20 to 25 degrees Celsius, and the thickness of the metal Pd front electrode is 5 to 15 nanometers.

[0037] Furthermore, metal In electrodes are pressed on the metal Pd front electrode and the Si substrate respectively, and wires are led out to obtain a device.

[0038] The method for preparing the above device specifically comprises the following steps:

[0039] (1) Select a p-Si substrate with a size of 1 cm × 1 cm, clean it in an ultrasonic machine with deionized water, acetone, and anhydrous ethanol for 20 min, and dry it for later use.

[0040] (2) placing the dried Si substrate into a vacuum chamber, and using radio frequency magnetron sputtering technology in an argon environment to bombard a Pd target with ionized argon ions to deposit a Pd thin film layer on the surface of the Si substrate; the target purity is 99.9%, the argon pressure is maintained at 1.2 Pascals, the target-substrate distance is 50 mm, the deposition temperature of the film is 20-25 degrees Celsius, the deposition time is about 30 seconds, and the film thickness is 10-20 nanometers;

[0041] (3) Place a Si substrate covered with a Pd thin film layer into the back end of CVD, place a quartz boat containing 50 mg of Te powder into the front end of the tube furnace, set the evaporation temperature to 430°C, and the back end reaction temperature to 480°C. Pass argon and hydrogen. The argon flow rate is 45 sccm, the hydrogen flow rate is 5 sccm, and the temperature rise rate is 5 degrees Celsius per minute. Keep it at 480 degrees Celsius for 150 minutes, and then cool it naturally to room temperature. Obtain a PdTe2 substrate on Si.

[0042] (4) Place the Si substrate with the PdTe2 substrate into the back end of the CVD, place a quartz boat containing 50 mg of Sb powder into the front end of the tube furnace, set the evaporation temperature to 400°C, set the back end reaction temperature to 100°C, introduce argon and oxygen, the argon flow rate is 45 sccm, the oxygen flow rate is 5 sccm, the temperature rise rate is 5 degrees Celsius per minute, maintain the set temperature for 30 minutes, and then cool naturally to room temperature; obtain a Sb2O3 two-dimensional thin film on the PdTe2 substrate.

[0043] (5) taking out the sample obtained in step (4), covering the surface of the Sb2O3 two-dimensional thin film layer grown on the PdTe2 surface with a mask, and then placing the sample in a vacuum chamber; using a DC magnetron sputtering technique, using ionized argon ions to bombard a metal Pd target, and depositing a metal Pd front electrode on the surface of the Sb2O3 two-dimensional thin film layer grown on the PdTe2 surface; the Pd target is a Pd metal target, and the purity of the target is 99.9%; the argon gas pressure is maintained at 5.0 Pascals, the target-substrate distance is 50 mm, the deposition temperature of the metal Pd film is 20 to 25 degrees Celsius, and the thickness of the metal Pd front electrode is 5 to 15 nanometers;

[0044] (6) The metal In electrode is pressed onto the metal Pd front electrode and the Si substrate respectively, and the metal Cu wire is led out to complete the preparation of the device.

[0045] The device having broadband self-driven light detection capability can be used in the preparation of broadband self-driven photodetectors.

[0046] The effects of the present invention are further described below in conjunction with the performance measurement results:

[0047] Figure 1 The XRD characterization diagram of the prepared device is shown in Figure 2. From the XRD characterization diagram, it can be seen that the Sb2O3 two-dimensional film has good crystallization properties.

[0048] Figure 2 Schematic diagram of the structure for measuring the light detection performance of the prepared device.

[0049] Figure 3 The periodic response performance of the device to light under the condition of an applied voltage of 0 volts. As shown in the figure, the light response characteristics of the device under 255nm, 808nm, 905nm and 1550nm laser irradiation are respectively shown. By changing the light environment in which it is located, the prepared thin film device shows good light response performance and has the advantages of stable performance.

[0050] Figure 4 The SEM characterization image of the Sb2O3 two-dimensional film shows that the Sb2O3 two-dimensional film is successfully grown on the surface of the Si substrate.

[0051] Figure 5 This is a SEM characterization image of PdTe2. From the SEM characterization image, it can be seen that PdTe2 is successfully grown on the surface of the Si substrate.

[0052] Figure 6 This is a SEM characterization image of the Sb2O3 two-dimensional film grown on the PdTe2 surface. From the SEM characterization image, it can be seen that the Sb2O3 two-dimensional film is successfully grown on the PdTe2 surface.

Claims

1. A broadband self-driven electrical detector based on 2D Sb2O3 / PdTe2 / Si heterojunction, characterized in that: It includes a metal In point electrode, a metal Pd front electrode, a Sb2O3 two-dimensional thin film layer grown on the surface of PdTe2, a Si single crystal substrate and a metal In back electrode. The Sb2O3 two-dimensional thin film layer grown on the surface of PdTe2 is arranged on the surface of the Si substrate, the metal Pd front electrode is on the surface of the Sb2O3 two-dimensional thin film layer grown on the surface of PdTe2, and the metal In electrode is pressed on the metal Pd front electrode and the surface of the Si substrate respectively.

2. A broadband self-driven electrical detector based on 2D Sb2O3 / PdTe2 / Si heterojunction according to claim 1, characterized in that: The Si substrate is a p-type Si single crystal substrate, has a resistivity of 0.1 to 1 ohm·cm, and a crystal plane orientation of (100).

3. A broadband self-driven electrical detector based on 2D Sb2O3 / PdTe2 / Si heterojunction and a method for preparing the same, characterized in that The following steps are involved: (1) Selecting a Si substrate and cleaning it; (2) Drying the cleaned Si substrate; (3) placing the dried Si substrate into a vacuum chamber, and using radio frequency magnetron sputtering technology in an argon environment to bombard a Pd target with ionized argon ions to deposit a Pd thin film layer on the surface of the Si substrate; the target purity is 99.9%, the argon pressure is maintained at 1.2 Pascals, the target-substrate distance is 50 mm, the deposition temperature of the film is 20-25 degrees Celsius, and the film thickness is 10-20 nanometers; (4) Place the Si substrate covered with the Pd thin film layer into the back end of the CVD, place the quartz boat containing 50 mg of Te powder into the front end of the tube furnace, set the evaporation temperature to 430°C, and the back end reaction temperature to 480°C. Pass gas at a temperature rise rate of 5°C per minute, maintain the temperature at 480°C for 150 minutes, and then cool naturally to room temperature; obtain a PdTe2 substrate on Si. (5) The Si substrate with the PdTe2 substrate was placed in the back end of the CVD, and a quartz boat containing 50 mg of Sb powder was placed in the front end of the tube furnace. The evaporation temperature was 400°C, the back end reaction temperature was 100°C, and the gas was introduced. During the reaction, the pressure in the tube was always maintained at 1 Pa, and the temperature rise rate was 5 degrees Celsius per minute. After reaching the set temperature, it was kept warm for 30 minutes and then naturally cooled to room temperature. A Sb2O3 two-dimensional thin film was obtained on the PdTe2 substrate. (6) taking out the sample obtained in step (5), covering the surface of the Sb2O3 two-dimensional thin film layer grown on the PdTe2 surface with a mask, and then placing the sample in a vacuum chamber; using a DC magnetron sputtering technique, bombarding a metal Pd target with ionized argon ions, and depositing a metal Pd front electrode on the surface of the Sb2O3 two-dimensional thin film layer grown on the PdTe2 surface; the Pd target is a Pd metal target, and the purity of the target is 99.9%; the argon gas pressure is maintained at 5.0 Pascals, the target-substrate distance is 50 mm, the deposition temperature of the metal Pd film is 20 to 25 degrees Celsius, and the thickness of the metal Pd front electrode is 5 to 15 nanometers; (7) The metal In electrode is pressed onto the metal Pd front electrode and the Si substrate respectively, and the metal Cu wire is led out to complete the preparation of the device.

4. The method for preparing a broadband self-driven electrical detector based on a 2D Sb2O3 / PdTe2 / Si heterojunction according to claim 3, characterized in that: In step (1), the Si substrate is a p-type Si single crystal substrate with a size of 10 mm×10 mm and a resistivity of 0.1 to 1 ohm·cm; the cleaning process is as follows: the Si substrate is ultrasonically cleaned in high-purity alcohol and acetone solutions for multiple times, each cleaning time being 20 minutes.

5. The method for preparing a broadband self-driven electrical detector based on a 2D Sb2O3 / PdTe2 / Si heterojunction according to claim 3, characterized in that: In step (6), the mask sheet material is stainless steel, with a thickness of 0.1 mm, a size of 12 mm×12 mm, and an aperture size of 5 mm×5 mm.

6. The method for preparing a broadband self-driven electrical detector based on a 2D Sb2O3 / PdTe2 / Si heterojunction according to claim 3, characterized in that: In step (4), the gases introduced are argon and hydrogen, with the argon flow rate being 45 sccm and the hydrogen flow rate being 5 sccm.

7. The method for preparing a broadband self-driven electrical detector based on a 2D Sb2O3 / PdTe2 / Si heterojunction according to claim 3, characterized in that: In step (5), the gases introduced are argon and oxygen, with the argon flow rate being 45 sccm and the oxygen flow rate being 5 sccm.

8. The method for preparing a broadband self-driven electrical detector based on a 2D Sb2O3 / PdTe2 / Si heterojunction according to claim 3, characterized in that: In step (7), the purity of the raw material In used for the metal In electrode is 99.5%, the size and thickness of the metal In electrode on the metal Pd front electrode are 1 mm×1.5 mm and 1 mm respectively, the size and thickness of the metal In electrode on the Si substrate are 10 mm×10 mm and 2 mm respectively, and the diameter of the Cu wire is 0.1 mm.

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