A method for preparing a palladium diselenide wafer and applications thereof

Abstract

The application relates to the technical field of two-dimensional material preparation, and particularly relates to a PdSe2 wafer-level preparation method and application. The application verifies whether the temperature and gas flow rate in a tubular furnace are uniformly distributed in the selenization process by fluid dynamics simulation of the temperature and gas flow rate in the tubular furnace; verifies the influence of the selenization temperature on the synthesis of a PdSe2 film; verifies the influence of the precursor thickness on the preparation of PdSe2; and compares the influence of the temperature and thickness on the quality of PdSe2 synthesized by evaporating Pd metal through an electron beam and then selenizing to widen the growth parameter window. Finally, a high-performance PdSe2 wafer-level is prepared, and the preparation method is further applied to prepare a PdSe2 device, and a field effect transistor and a photoelectric detector are constructed. The application can provide an important reference for silicon process compatible preparation of a wafer-level high-quality PdSe2 two-dimensional material.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of two-dimensional material preparation, and in particular to a palladium diselenide wafer-level preparation method and application. BACKGROUND

[0002] There are two synthetic routes for palladium diselenide. The first is a top-down method, including mechanical exfoliation of bulk PdSe2 crystals. The second is a bottom-up strategy, involving molecular beam epitaxy, chemical vapor deposition. First, the domains of PdSe2 prepared by the above methods are usually micro-transferred, which limits its application in electronics. In contrast, the emerging metal selenization strategy has achieved full coverage of PdSe2 films on Si / SiO2, dielectric sapphire or textured heterostructures, which is compatible with traditional Si-based semiconductor processing technology. However, magnetron sputtering is usually used to deposit metal or oxide films with micron-level thickness for microelectronic applications such as photovoltaic cells or memory devices. Sputtering technology results in the prepared thin films having the disadvantages of large roughness and small particles.

[0003] Electron beam evaporation of gold thin films is usually used for wafer-level device manufacturing. In fact, high-quality two-dimensional materials, including MoTe2, WSe2, have been prepared by electron beam evaporation of metal plus sulfidation. Therefore, using electron beam evaporation technology to directly synthesize PdSe2 thin films with Pd metal as a precursor can improve the quality of PdSe2 thin films. However, the synthesis parameter window for electron beam evaporation of Pd thin films and post-selenization synthesis of PdSe2 thin films is still narrow, and the growth mechanism is not clear. SUMMARY

[0004] In view of the problems in the background art, a palladium diselenide wafer-level preparation method and application are provided.

[0005] The application provides a palladium diselenide wafer-level preparation method, which verifies whether the temperature and gas flow rate in the tube furnace during selenization are uniformly distributed by fluid dynamics simulation of the temperature and gas flow rate in the tube furnace; verifies the influence of selenization temperature on the synthesis of palladium diselenide thin films; verifies the influence of precursor thickness on the preparation of palladium diselenide; and performs palladium diselenide wafer-level preparation by combining the parameters obtained through the above verifications, the steps being as follows:

[0006] S1, substrate cleaning;

[0007] S2, deposition of a metal thin film;

[0008] S3, preparation of a palladium diselenide material;

[0009] S4, preparation of wafer-level palladium diselenide.

[0010] Preferably, by performing multi-physical field simulation calculation, and turning to dynamic control, selenium vapor capture is used to maintain chemical equilibrium environment to promote uniform growth.

[0011] Preferably, the optimal temperature range for direct selenization of palladium metal is 400-500℃.

[0012] Preferably, the optimal thickness of PdSe2 is 6nm.

[0013] Preferably, in S1, the substrate is cleaned by using acetone, isopropyl alcohol, and deionized water in sequence, which is poured over the substrate and cleaned in an ultrasonic cleaning instrument; then the substrate is dried or wiped clean with a dust-free cloth, and finally cleaned with oxygen plasma.

[0014] Preferably, in S2, an electron beam evaporation coater is used to evaporate Pd film; the power of the electron gun is 3kW; the working temperature of the water chiller is 25℃, and the flow rate is 12.3LPM.

[0015] Preferably, the target material is pre-dissolved and evaporated by manual pre-melting and deposition of the film layer, and the output power is manually adjusted to reach the required deposition rate; the power of Pd pre-melting is set to about 100kW, and the rate is controlled to be less than 0.1nm / s.

[0016] Preferably, the specific operation of S3 is as follows:

[0017] S31, place the palladium film deposited on the substrate in the second temperature zone of the tube furnace, weigh 2g of selenium powder and place it in the ceramic boat in the first temperature zone;

[0018] S32, by vacuum pump, the tube becomes a vacuum state, in the protection atmosphere of Ar and H2, the temperature of the area where the selenium powder is located is increased to 600℃ at a rate of 25℃ / min, at the same time, the temperature zone for substrate treatment is increased to 400℃ at a rate of 19℃ / min;

[0019] S33, post-selenization treatment of Pd thin film, selenization time is set to 10min;

[0020] S34, ventilate and quickly cool the selenium powder area to room temperature for 2min;

[0021] S35, stop heating the substrate area and pull away the downstream area to completely expose the substrate area;

[0022] S36, the palladium thin film is synthesized into a palladium diselenide thin film after selenization.

[0023] Preferably, the specific operation of S4 is as follows:

[0024] S41, using high temperature adhesive tape to fix the substrate, and fixing it into a pentagonal shape, using a coating instrument to evaporate a four-inch pentagonal palladium film as a precursor;

[0025] S42, through the program control of the tube furnace, the temperature of the selenium evaporation temperature and the growth area and the temperature of the holding area are uniformly set to 450 DEG C: first, increase to 200 DEG C at a rate of 5 DEG C / min, then increase to 450 DEG C at a rate of 4 DEG C / min, and then start synthesizing the palladium diselenide film, and the growth time is extended to 180 min;

[0026] S43, after the selenization, through the program control of the tube furnace: first, decrease to 200 DEG C at a rate of 1.4 DEG C / min, then stop the program, and use the ventilation equipment to gradually cool to room temperature.

[0027] The application further provides an application of the palladium diselenide wafer prepared by the palladium diselenide wafer preparation method, which comprises the following steps: preparing a palladium diselenide device, and then applying the palladium diselenide device to build a field effect transistor and a photoelectric detector.

[0028] Compared with the prior art, the application has the following beneficial technical effects:

[0029] The application verifies whether the temperature and the gas flow rate in the tube furnace are uniform during the selenization process through fluid dynamics simulation of the temperature and the gas flow rate in the tube furnace, verifies the influence of the selenization temperature on the synthesis of the palladium diselenide film, verifies the influence of the precursor thickness on the preparation of the palladium diselenide, compares the influence of the temperature and the thickness on the quality of the PdSe2 synthesized by electron beam evaporation of Pd metal and post-selenization to broaden the growth parameter window. Finally, a high-performance palladium diselenide wafer is prepared, and the preparation method is further applied to prepare a palladium diselenide device and build a field effect transistor and a photoelectric detector. The application can provide an important reference for silicon process compatible preparation of wafer-level high-quality PdSe2 two-dimensional material. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 for a 1.5*1.5cm 2 silicon wafer substrate;

[0031] Figure 2 for the schematic diagram of the chamber in the electron beam evaporation coating instrument;

[0032] Figure 3 for the flow chart of the preparation of the palladium diselenide by the chemical vapor deposition method;

[0033] Figure 4 for the schematic diagram of the color change of the palladium film before and after selenization;

[0034] Figure 5Schematic diagrams of the results of computational fluid dynamics simulation of the temperature and gas flow rate in the furnace: (a) is a temperature distribution diagram of the wafer substrate containing the palladium diselenide film; (b) is a gas flow rate distribution diagram during growth of the palladium diselenide film; (c) is an enlarged view of the area in (a); (d) is an enlarged view of the gas flow rate near the palladium film on the selenium source and the silicon wafer substrate;

[0035] Figure 6 Schematic diagrams of the results of temperature experiments for palladium diselenide formation: (a) is a Raman spectrum of palladium diselenide material grown at 400℃, 500℃, 600℃, 700℃, and 800℃; (b-f) are optical images of palladium diselenide films grown at 400℃, 500℃, 600℃, 700℃, and 800℃;

[0036] Figure 7 Raman spectra and optical micrographs of palladium diselenide before and after seleniumization;

[0037] Figure 8 Pictures of Pd films before and after seleniumization: (a-c) are images of Pd films with different thicknesses (0.5 nm, 1 nm, and 2 nm); (d-f) are seleniumized samples (PdSe2) on Si / SiO2 substrates;

[0038] Figure 9 Schematic diagrams of the results of palladium diselenide film thickness adjustment for different thicknesses: (g-i) are optical micrographs of palladium diselenide films with thicknesses of 1.5 nm, 3 nm, and 6 nm, respectively; (j-l) are atomic force micrographs of palladium diselenide films with the three thicknesses; (m-o) are corresponding Raman spectra of the palladium diselenide films;

[0039] Figure 10 Schematic diagrams of a palladium diselenide device: (a) is a mask picture; (b) is a picture of a palladium diselenide device; (c) is an optical micrograph of a channel of the palladium diselenide device. DETAILED DESCRIPTION

[0040] Example 1

[0041] The present application proposes a palladium diselenide wafer-level preparation method, and the steps are as follows:

[0042] I. Substrate cleaning

[0043] The substrate used in the present application is Si / SiO2 (doped with 300 nm of silicon dioxide), which is defined as a square of 2×2 cm 2 . A four-inch substrate is cut into equal-sized rectangles by a glass knife. Figure 1 1.5×1.5 cm 2The silicon wafer substrate is cleaned. The small wafer substrate is placed in a cleaning basket, and the cleaning basket is placed in a beaker. The cleaning basket is sequentially immersed in acetone, isopropyl alcohol, and deionized water containing the substrate, and is placed in an ultrasonic cleaning instrument for cleaning for 15 minutes. Then the substrate is dried or wiped clean with a clean cloth. Finally, oxygen plasma cleaning is performed to remove impurities and dust on the surface of the substrate, so that the Pd film to be evaporated can be closely attached to the substrate, the uniformity of the precursor is ensured, and the PdSe2 after seleniumization is full film coverage.

[0044] II. Deposition of metal thin film

[0045] The present application needs to evaporate a Pd metal film as a seleniumization precursor. The Pd film is evaporated by using an electron beam evaporation film instrument of HHVATS500 system, and the power of the electron gun is 3kW. First, ensure that the N2 pressure is normal, which can ensure that the vacuum state of the film instrument chamber can be broken, the gas pressure is set to 0.1MPa, and the gas valve switch of the film instrument can be controlled, the gas pressure is set to 0.6MPa. Ensure that the working temperature of the water chiller reaches 25℃, and the flow rate reaches 12.3LPM. To ensure that the temperature of the film instrument during operation is kept at room temperature. When the pressure in the chamber reaches atmospheric pressure, open the chamber door, fix the sample on the sample holder with high-temperature tape, and invert it above the electron gun sensor. Put the palladium target into the graphene crucible, and then put it into the designated position in the chamber, and close the door. The situation in the electron beam evaporation film instrument chamber is as shown in Figure 2 .

[0046] Then vacuumize, so that the vacuum pressure in the chamber is higher than 5.0x10 -6 Pa, start film deposition. The present application evaporates Pd films with thicknesses of 0.5nm, 1nm, and 2nm. Since the evaporated Pd film is very thin, manual pre-melting and deposition film layer are needed to pre-dissolve and evaporate the target. The output power is manually adjusted to reach the required deposition rate. In this paper, the power of Pd pre-melting is about 100kW, and the rate is controlled at

[0047] III. Preparation of palladium diselenide material

[0048] The palladium film deposited on the substrate is placed in the second temperature zone of the tube furnace, 2g of selenium powder is weighed and placed in the ceramic boat, and the ceramic boat is placed in the first temperature zone. Figure 3The flow chart of the chemical vapor deposition method for preparing PdSe2 is shown. The tube is made vacuum by vacuum pump, the temperature of the area where the selenium powder is located is increased to 600℃ at a rate of 25℃ / min in the protection atmosphere of Ar and H2, while the temperature of the area for substrate processing is increased to 400℃ at a rate of 19℃ / min. Then the Pd film is subjected to post-selenization treatment, and the selenization time is set to 10 min. The area of the selenium powder is quickly cooled to room temperature by ventilation for 20 min to stop the evaporation of the selenium powder and prevent the thickness of the PdSe2 film from being uncontrollable. Then the substrate heating area is stopped and the downstream area is pulled away to completely expose the substrate area for cooling treatment of the material. Finally, the Pd film is selenized to synthesize the PdSe2 film.

[0049] Four, preparation of wafer-level PdSe2

[0050] The substrate Si / SiO2 is fixed by using high-temperature adhesive tape and is fixed into a pentagonal shape, and a four-inch pentagonal Pd metal film is evaporated by a coating instrument as a precursor. Figure 4 a) The selenization temperature, selenization time and quality of selenium source are optimized. The volume of the giant horizontal tube furnace is large, and in order to ensure that the selenium vapor can fully react with the Pd film, the mass of the selenium powder is increased to three times of the original. In addition, the temperature is increased slowly during the preparation process and the temperature in the tube is relatively high, in order to ensure the uniformity of the PdSe2 film and the safety of the experiment, the temperature is programmed to rise and fall by the tube furnace, in order to make the temperature in the tube uniform, the evaporation temperature of selenium, the growth area and the temperature of the holding area are all set to 450℃. First, increase the temperature to 200℃ at a rate of 5℃ / min, then increase the temperature to 450℃ at a rate of 4℃ / min, and then start to synthesize the PdSe2 film, and the growth time is extended to 180 min. After selenization, instead of rapid cooling, the temperature is programmed to fall by the tube furnace, first at a rate of 1.4℃ / min to 200℃, then stop the program, and use the ventilation equipment to naturally cool down to room temperature. This method is used to prepare a four-inch wafer-level PdSe2 film on a Si / SiO2 substrate Figure 4 b). Figure 4 It can be seen that the color of the Pd film changes significantly before and after selenization.

[0051] Five, calculation results of temperature and gas flow rate in the tube furnace by fluid dynamics simulation

[0052] In order to verify whether the temperature and gas flow rate in the tube furnace during selenization are uniformly distributed, multi-physical field simulation calculation is carried out, and the dynamics control is turned to the selenium vapor capture to maintain the chemical equilibrium environment to promote uniform growth. The computational fluid dynamics simulation in the horizontal tube furnace Figure 5) shows that the gas flow rate and temperature are uniformly distributed on the wafer surface and the ceramic boat (used to contain Se powder). The ceramic boat is installed in a quartz test tube, simulating the carefully constructed vapor capture strategy for growing high-quality monolayer graphene.

[0053] Six, the effect of selenization temperature on the synthesis of palladium diselenide film

[0054] Temperature is an important parameter in chemical experimental reaction system. First of all, the exploration of selenium heating temperature, the melting point of selenium is 220℃, so selenium can be gasified at 200℃, but the gasification of selenium is too low, which will lead to slow reaction, and the reaction of palladium and selenium cannot be completely reacted into palladium diselenide. The evaporation temperature of selenium is too high, which will lead to the termination of the reaction in advance, and the surface of the prepared palladium diselenide is not uniform. It is proved that selenium can be completely evaporated into selenium vapor at 600℃, which can ensure sufficient selenium source for the reaction and ensure the high quality and uniformity of the prepared palladium diselenide.

[0055] Secondly, the exploration of growth temperature, the suitable temperature plays an important role in reducing the activation energy of precursor. Low temperature leads to too low reaction rate, which cannot support the activation energy required by the reaction, and high temperature energy is too high, which will lead to the gasification of palladium diselenide. In order to explore the most suitable parameter space for the growth of palladium diselenide, temperature dependent growth experiments were carried out, including substrate temperature of 400℃, 500℃, 600℃, 700℃ and 800℃. 0.5nm Pd metal film was evaporated as precursor before selenization, and bare Si / SiO2 substrate was used for comparison. The structure and surface morphology of palladium diselenide samples prepared at different temperatures were characterized by Raman spectrum test and optical microscope image. Figure 6 a is the Raman spectrum of the sample prepared by selenization at different temperatures, and it is found that the samples selenized at 400℃ and 500℃ appear the characteristic Raman peaks of palladium diselenide (A 1 g and A 3 g ). While the Raman spectrum of selenization temperature greater than 600℃ has no A 1 g and A 3 g characteristic peaks appear. Only the bare Si / SiO2 substrate matches well with the Raman spectrum. Figure 6 b and 6c optical microscope images can also be seen between the substrate (upper right corner) and the palladium diselenide film. Figure 6 d, e can be seen that from 600℃, the shrinkage of Pd related area is weak. The sample even disappears at 800℃ ( Figure 6 f), similar to Figure 6b, c the bare substrate in the upper right corner, it is inferred that the loss of selenium at higher growth temperatures of 600-700 °C does not allow the formation of palladium diselenide, since the palladium metal as catalyst remains unchanged and does not react with selenium at high temperatures. When the growth temperature reaches 800 °C, the high temperature causes the desorption (also known as sublimation) of palladium-related atomic clusters from the surface. Based on the above experiments, the optimal temperature range for direct selenium of palladium metal is 400-500 °C.

[0056] In addition, whether palladium diselenide can be prepared by thermal deposition at low temperature is explored, and the growth temperature is adjusted to 300 °C, 320 °C, 350 °C and 380 °C. The synthesized samples are tested by Raman spectroscopy Figure 7 a) The samples prepared at the four temperatures all have the characteristic peaks of palladium diselenide. The morphology of the samples is optically characterized, and the palladium and selenium prepared at low temperature can also fully react and have good contact with the substrate (the bare Si / SiO2 in the upper left corner). This experiment also realizes low-temperature selenium at a temperature as low as 300 °C.

[0057] Seven, the effect of precursor thickness on the preparation of palladium diselenide

[0058] The band gap of palladium diselenide depends on its layer number (thickness). Therefore, palladium diselenide with different thicknesses is synthesized, and their electronic and photoelectric properties are compared. The traditional chemical vapor deposition strategy uses palladium-containing (such as PdCl2) powder and selenium powder to react, resulting in uncontrollable thickness of palladium diselenide material. In this experiment, the thickness of palladium diselenide can be determined according to the thickness of the palladium vapor deposition, and by vapor deposition of palladium metal, it is ensured that the palladium precursor on the substrate is fully film uniform coverage, and by direct selenium method to prepare palladium diselenide, it can ensure the full film coverage and consistency of palladium diselenide.

[0059] The thickness dependence of palladium diselenide is explored in this experiment. First, 0.5 nm, 1 nm and 2 nm palladium films are prepared, and they are selenized, and the pictures of palladium films with different thicknesses and palladium diselenide are compared. Figure 8 a-c can be seen that the color contrast of the palladium film area becomes darker as the thickness of the palladium film increases, from Figure 8 d-f can be seen that the pictures of palladium diselenide thin films after selenization show stronger color contrast compared to their metal precursors.

[0060] In fact, from Figure 9 g-i optical micrographs show a similar trend of color shrinkage with increasing thickness. Figure 9j-l shows the atomic force microscopy image of the palladium diselenide film, which can be seen that the palladium diselenide film surface is extremely uniform, and the impurities are less. In this experiment, the thickness of the palladium precursor evaporated is 0.5 nm, 1 nm and 2 nm. The height between the palladium diselenide and the bare substrate is measured, that is, the thickness of the three samples is 1.5 nm, 3 nm and 6 nm respectively. The surface roughness of the three thickness samples is measured by root mean square statistics, which is 1.3 nm, 1.8 nm and 3.9 nm respectively.

[0061] Example two

[0062] After the palladium diselenide wafer level is prepared by the palladium diselenide wafer level preparation method in example one, the palladium diselenide device is further prepared. The specific operation is as follows:

[0063] The palladium diselenide film layer on the Si / SiO2 substrate is covered with a mask plate Figure 10 a), 5 nm Ti and 50 nm Au are deposited in turn by using an electron beam evaporation coating instrument as the contact point of the electrode. Figure 10 b is the prepared palladium diselenide device. Figure 10 The blue bare strip part in the pink square in b is defined as the device channel part. The device is characterized by optical microscopy image Figure 10 c), the channel length of the palladium diselenide device is measured to be 50 μm, and the width is 1000 μm.

[0064] The above-mentioned palladium diselenide device can construct a palladium diselenide-based field effect transistor and a photoelectric detector, and the electrical and photoelectronic properties of the palladium diselenide are studied by testing. The performance indicators for comparison are the mobility of the field effect transistor, the detection rate and the response of the photoelectric detector.

[0065] The mobility of the field effect transistor can be calculated by the following formula using the linear region of the output curve:

[0066]

[0067] Wherein, C g is the capacitance of the gate insulating layer (300 nm Si / SiO2); Cg=ε0ε r r, the vacuum dielectric constant and the relative dielectric constant of Si / SiO2, d is the thickness of the substrate, wherein d is 300 nm. L and W are the channel length and width of the field effect transistor, which are 50 μm and 1000 μm respectively. V d is the applied source voltage. is the slope of the linear region of the output curve of the field effect transistor of the palladium diselenide.

[0068] Responsivity and detectivity are the main parameters for evaluating the performance of photoelectric detector. The formula for calculating the responsivity is as follows:

[0069]

[0070] Wherein R is the responsivity, I ph is the photocurrent, λ is the power intensity of the incident light on the effective area of the device. S is the effective area of the laser irradiation on the channel of the device material.

[0071] The formula for calculating the detectivity is as follows:

[0072]

[0073] Wherein A is the effective area between the source electrode and the drain electrode. R is the responsivity of the device, which can be obtained by the formula for calculating the responsivity. q represents the basic charge coefficient, and the value is 1.6×10 -19 C. I dark is the current in the dark state.

[0074] The embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited thereto, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present application.

Claims

1. A method for the preparation of a palladium diselenide wafer, characterized in that, The temperature and gas flow rate in the tube furnace during the selenization process are verified by fluid dynamics simulation, to verify whether the temperature and gas flow rate in the tube furnace during the selenization process are uniform; to verify the influence of the selenization temperature on the synthesis of the PdSe2 film; and to verify the influence of the thickness of the precursor on the preparation of the PdSe2 film. Based on the parameters obtained through the above verification, the wafer-level preparation of the PdSe2 film is carried out, and the steps are as follows: S1, substrate cleaning; in S1, the substrate is cleaned by using acetone, isopropyl alcohol and deionized water in sequence, the substrate is immersed in the cleaning agent, and then placed in an ultrasonic cleaning instrument for cleaning; then the substrate is dried or wiped clean with a dust-free cloth, and finally cleaned by using oxygen plasma; S2, deposition of metal thin film; in S2, electron beam evaporation coater is used to evaporate Pd film; power of electron gun is 3 KW; working temperature of water chiller is 25 ° C, flow rate is 12.3 Lpm; target material is pre-dissolved and evaporated by using manual pre-melting and deposition of film layer, output power is manually adjusted to reach the required deposition rate; power of Pd pre-melting is set to about 100 KW, and rate is controlled to be 2.8-3.2 A / s; S3, preparation of the PdSe2 film; the specific operation of S3 is as follows: S31, the Pd film deposited on the substrate is placed in the second temperature zone of the tube furnace, 2g of selenium powder is weighed and placed in a ceramic boat, and the ceramic boat is placed in the first temperature zone; S32, the tube is brought to a vacuum state by a vacuum pump, and the temperature of the region in which the selenium powder is located is raised to 600°C at a rate of 25 ° C / min in an Ar and H2 atmosphere, while the temperature region for substrate processing is raised to 400 ° C at a rate of 19 ° C / min; S33, post-selenization treatment is performed on the Pd film, and the selenization time is set to 10min; S34, the selenium powder area is quickly cooled to room temperature by ventilation for 2min; S35, the substrate heating area is stopped, and the downstream area is pulled away to completely expose the substrate area; S36, the Pd film is selenized to synthesize a PdSe2 film; S4, wafer-level preparation of the PdSe2 film; the specific operation of S4 is as follows: S41, the substrate is fixed by using a high-temperature adhesive tape, and the substrate is fixed into a pentagonal shape, a four-inch pentagonal Pd metal film is deposited by using a film deposition instrument as a precursor; S42, the temperature of the tube furnace program control, selenium evaporation temperature and growth region and the temperature of the holding zone are set to 450 ° C: first to 5 ° C / min, then to 450 ° C / min, then to 450 ° C / min, then to 450 ° C, the synthesis of palladium diselenide film begins, and the growth time is extended to 180 min; S43, after the end of selenization, the temperature is decreased by a programmed control of the tubular furnace: first to 200 ° C at a rate of 1.4°C / min, then the program is stopped and the natural cooling is performed by means of ventilation devices to gradually decrease the temperature to room temperature; Through the simulation calculation of multiple physical fields, and the conversion to kinetic control, the selenium vapor capture is used to maintain a chemical equilibrium environment to promote uniform growth; The optimal temperature range for direct selenization of the Pd metal is 400-500°C; The optimal thickness of the PdSe2 film is 6nm.

2. Use of a palladium diselenide wafer prepared by the process according to claim 1, characterized in that The PdSe2 film is applied to construct a field effect transistor and a photodetector.

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