Preparation of 10.6 [mu] m flexible photoelectric detector based on novel Ta2PtSe7 alloy

Abstract

The invention relates to the technical field of flexible photoelectric devices, in particular to preparation of a 10.6 mu m flexible photoelectric detector based on a novel Ta2PtSe7 alloy, high-purity Ta2PtSe7 single crystal is prepared from a tantalum elementary substance, a platinum elementary substance and a selenium elementary substance, a polydimethylsiloxane thin film is used as an intermediate carrier after mechanical stripping, and the flexible photoelectric detector based on the novel Ta2PtSe7 alloy is prepared. A Ta2PtSe7 single crystal is transferred to a flexible substrate, spin coating of photoresist, laser direct writing and exposure development are carried out, a brand new flexible wearable photoelectric detector is obtained, and the working wavelength range of the photoelectric detector is remarkably expanded and can reach 10.6 microns; and due to the special structure of Ta2PtSe7, the Ta2PtSe7 has better response speed and responsivity, ultrahigh air stability and better flexible anti-fatigue performance, has huge application potential in the field of mid-infrared detection, and has wide application prospects compared with the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible optoelectronic devices, and particularly to the preparation of a 10.6μm flexible photodetector based on a novel Ta 2 PtSe 7 alloy. Background Art

[0002] A photodetector is a device that converts optical signals into electrical signals, and its working principle is based on the photoelectric effect, that is, when light irradiates the surface of a substance, the substance absorbs light energy and converts it into electrical energy. With the continuous progress of modern technology, photodetectors are widely used in fields such as communication, medical treatment, military, and scientific research, such as optical signal reception in fiber optic communication systems, optical imaging, lidar, infrared detection, spectral analysis, and quantum information. Among these applications, infrared detectors are particularly important because they can detect radiation in the invisible light band and are widely used in thermal imaging, night vision devices, gas analysis, etc. Traditional infrared detectors mostly rely on materials such as silicon, gallium arsenide, and indium gallium, but these materials have limited photoelectric response in a specific wavelength range and lack flexibility, which limits their applications in wearable devices, intelligent sensors, and integrated systems.

[0003] With the continuous in-depth research of new materials, two-dimensional materials have become a hot topic in the research of photodetectors due to their unique electronic structure and excellent optoelectronic properties. Two-dimensional materials are a class of layered materials with atomic-level thickness, and their electrons can only move freely in two dimensions, while the third dimension is affected by the quantum confinement effect. Due to their unique physical, chemical, and optical properties, these materials show broad application potential in multiple fields. These new materials not only show advantages in light absorption, carrier mobility, etc., but also have great potential in the design and preparation of flexible photodetectors.

[0004] Traditional photodetectors are usually made of rigid materials and are difficult to meet the requirements of emerging application fields such as wearable devices, flexible electronics, and intelligent sensors for flexibility and efficient energy conversion. With the increasing demand for flexible electronic devices, the development of new flexible photodetectors has become a research hotspot.

[0005] In the prior art, for example, the patent technical literature CN114203915A discloses a flexible organic photodetector based on a thin-layer metal electrode and its preparation method. The flexible organic photodetector includes a flexible substrate, a thin-layer metal anode, a hole extraction layer, a hole transport layer, a photosensitive layer, an electron transport layer, and a metal cathode arranged in sequence; the flexible organic photodetector prepared in this invention has the advantages of good stability and low power consumption, but the detection range of the flexible photodetector still needs to be improved.

[0006] Therefore, according to the related technologies described above, it is urgent to develop a preparation method for a 10.6 μm flexible photodetector based on a novel Ta 2 PtSe 7 alloy. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide a preparation method for a 10.6 μm flexible photodetector based on a novel Ta 2 PtSe 7 alloy, so as to solve the problems of small detection range and poor stability of flexible photodetectors in the prior art.

[0008] Based on the above purpose, the present invention provides a preparation method for a 10.6 μm flexible photodetector based on a novel Ta 2 PtSe 7 alloy.

[0009] A preparation method for a 10.6 μm flexible photodetector based on a novel Ta 2 PtSe 7 alloy includes the following steps:

[0010] Step A1. Place the Ta 2 PtSe 7 single crystal on Scotch tape for mechanical exfoliation, and then stick the polydimethylsiloxane film to the position where there are more Ta 2 PtSe 7 crystal flakes. Use a cotton swab to squeeze to ensure full contact between the polydimethylsiloxane film and the Ta 2 PtSe 7 crystal flakes. After 6 - 9 minutes, separate the polydimethylsiloxane film from the tape, then stick the polydimethylsiloxane film to the flexible substrate, and apply pressure on the surface of the polydimethylsiloxane film. After 4 - 7 minutes, remove the polydimethylsiloxane film to obtain a Ta 2 PtSe 7 single crystal film;

[0011] Step A2. Spin - coat photoresist on the Ta 2 PtSe 7 single crystal film using a spin coater, and then obtain a sample covered with an electrode pattern after laser direct writing, exposure and development. Then use electron beam evaporation to deposit a titanium - gold composite film at the pattern position, and thus obtain a 10.6 μm flexible photodetector based on a novel Ta 2 PtSe 7 alloy. 2 PtSe 7 Preferably, in Step A1, the Ta

[0012] described 2PtSe 7 The preparation method of single crystal is as follows:

[0013] Step B1. Weigh tantalum, platinum and selenium respectively, mix them evenly and then grind them in a mortar for 5 - 10 min, and then use a tablet press mold with a diameter of 10 mm to press tablets to obtain substance A;

[0014] Step B2. Place substance A in a quartz tube with an outer diameter of 13 mm, and use a mechanical pump and a molecular pump set to reduce the vacuum degree in the tube to V1, then seal the quartz tube with a hydrogen - oxygen mixture, and set the temperature to T1. After the quartz tube cools, place it in a muffle furnace, set the temperature to T2 and keep it warm for 28 - 30 d to obtain Ta 2 PtSe 7 single crystal.

[0015] Preferably, the molar ratio of tantalum, platinum and selenium in step B1 is 2:1:7;

[0016] The pressure during tablet pressing is 58 - 65 MPa and the tablet pressing time is 35 - 40 s.

[0017] Preferably, V1 < 10 -5 Torr;

[0018] The temperature T1 is 1880 - 1930 °C;

[0019] The temperature T2 is 700 - 740 °C.

[0020] Preferably, the flexible substrate in step A1 is polyethylene terephthalate.

[0021] Preferably, in step A2, the thickness of the titanium layer in the titanium - gold composite film is 8 - 12 nm and the thickness of the gold layer is 65 - 73 nm.

[0022] Advantages of the present invention:

[0023] The present invention provides a preparation method of a 10.6 - μm flexible photodetector based on a novel Ta 2 PtSe 7 alloy. By mixing tantalum, platinum and selenium evenly in a specific molar ratio, pressing tablets and then heating and insulating in a quartz tube, high - purity and high - crystalline - quality Ta 2 PtSe 7 single crystal is obtained. After mechanical exfoliation, using a polydimethylsiloxane film as an intermediate carrier, Ta 2 PtSe 7The single crystal was transferred onto a flexible substrate. After spin-coating photoresist, direct laser writing, exposure, and development, a novel flexible wearable photodetector was obtained. Its working wavelength range was significantly extended to 10.6 μm. And due to the special structure of Ta 2 PtSe 7 , it has good response speed and responsivity, ultra-high air stability, and good flexibility and anti-fatigue performance. As a result, the flexible photodetector prepared in this invention has great application potential in the field of mid-infrared detection. Compared with the prior art, it has a broad application prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] To more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only those of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 Schematic diagram of the Ta 2 PtSe 7 single crystal prepared in Example 1 of the present invention;

[0026] Figure 2 X-ray scan of the Ta 2 PtSe 7 single crystal prepared in Example 1 of the present invention;

[0027] Figure 3 Scanning electron microscope image of the Ta 2 PtSe 7 single crystal prepared in Example 1 of the present invention;

[0028] Figure 4 Point scanning energy spectrum of the Ta 2 PtSe 7 single crystal prepared in Example 1 of the present invention;

[0029] Figure 5 Area scanning energy spectrum of the Ta 2 PtSe 7 single crystal prepared in Example 1 of the present invention;

[0030] Figure 6 Schematic diagram of the Ta 2 PtSe 7 single crystal after mechanical exfoliation;

[0031] Figure 7 Schematic diagram of the Ta 2PtSe 7 Schematic diagram of a flexible device;

[0032] Figure 8 Ta prepared in Example 1 of the present invention 2 PtSe 7 Optoelectronic performance diagram of the flexible device;

[0033] Figure 9 Ta prepared in Example 1 of the present invention 2 PtSe 7 Comparison diagram of Raman spectra of the single crystal before and after being placed in air for one year;

[0034] Figure 10 Ta prepared in Example 1 of the present invention 2 PtSe 7 Flexibility test diagram of the flexible device. Detailed implementation manners

[0035] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to specific embodiments.

[0036] The sources and properties of some raw materials used in the present invention are as follows:

[0037] Tantalum metal was purchased from Dongguan Junheng Metal Materials Co., Ltd.; platinum metal was purchased from Shanghai Yinli Metal Materials Co., Ltd.; selenium metal was purchased from Sichuan High Purity Materials Technology Co., Ltd.; polydimethylsiloxane was purchased from Hubei Dahao Chemical Industry Co., Ltd.; polyethylene terephthalate was purchased from Hubei Dahao Chemical Industry Co., Ltd.

[0038] Example 1: Preparation of a 10.6 μm flexible optoelectronic detector based on a novel Ta 2 PtSe 7 alloy, including the following steps:

[0039] S1. Weigh 0.326 g of tantalum metal, 0.175 g of platinum metal and 0.500 g of selenium metal respectively (the molar ratio of tantalum metal, platinum metal and selenium metal is 2:1:7), mix them evenly and grind them in a mortar for 5 min, then use a tablet press mold with a diameter of 10 mm for tableting, and set the pressure during tableting to 58 MPa and the tableting time to 35 s to obtain Substance A;

[0040] S2. Place Substance A in a quartz tube with an outer diameter of 13 mm, and use a mechanical pump and a molecular pump set to reduce the vacuum degree in the tube to 9×10 -6 Torr, then seal the quartz tube with a hydrogen-oxygen mixture, set the temperature to 1880 °C, and after the quartz tube cools, place it in a muffle furnace, set the temperature to 700 °C and keep it warm for 28 - 30 d to obtain Ta2 PtS 7 Single crystal;

[0041] S3. 2 PtS 7 After the single crystal is placed on Scotch tape for mechanical peeling, the polydimethylsiloxane film is attached to the tape. 2 PtS 7 Use a cotton swab to squeeze the area where there are more crystal flakes to ensure that the polydimethylsiloxane film is close to the Ta 2 PtS 7 The crystal slices were fully in contact. After 6 minutes, the polydimethylsiloxane film was separated from the tape, and then the polydimethylsiloxane film was attached to a flexible polyethylene terephthalate substrate. Pressure was applied to the surface of the polydimethylsiloxane film. After 4 minutes, the polydimethylsiloxane film was removed to obtain Ta. 2 PtS 7 Single crystal thin film;

[0042] S4. Put Ta 2 PtS 7 The single crystal film is spin-coated with photoresist using a coating machine, and then directly written by laser, exposed and developed to obtain a Ta film covered with electrode patterns. 2 PtS 7 The sample was then deposited with a titanium-gold composite film at the pattern position using electron beam evaporation, wherein the thickness of the titanium layer was 8 nm and the thickness of the gold layer was 65 nm. 2 PtS 7 10.6μm flexible photodetector based on alloy.

[0043] Example 2: A novel Ta-based 2 PtS 7 The preparation of the 10.6 μm flexible photodetector of the alloy includes the following steps:

[0044] S1. Weigh 0.326 g of tantalum, 0.175 g of platinum and 0.500 g of selenium (the molar ratio of tantalum, platinum and selenium is 2:1:7) respectively, mix them evenly and grind them in a mortar for 6 minutes, and then use a tableting mold with a diameter of 10 mm to compress them, and set the tableting pressure to 59 MPa and the tableting time to 36 seconds to obtain substance A;

[0045] S2. Place substance A in a quartz tube with an outer diameter of 13 mm and use a mechanical pump and a molecular pump to reduce the vacuum degree in the tube to 9×10 -6 Torr, and then seal the quartz tube with hydrogen and oxygen mixture and set the temperature to 1890℃. After the quartz tube is cooled, place it in a muffle furnace and set the temperature to 710℃ and keep it for 28 days to obtain Ta2 PtSe 7 Single crystal;

[0046] S3. Place Ta 2 PtSe 7 After the single crystal is mechanically peeled off on Scotch tape, then stick the polydimethylsiloxane film onto the tape Ta 2 PtSe 7 At the position with more crystal flakes, use a cotton swab to squeeze to ensure that the polydimethylsiloxane film is in full contact with Ta 2 PtSe 7 The crystal flakes. After 7 minutes, separate the polydimethylsiloxane film from the tape, then stick the polydimethylsiloxane film onto the flexible polyethylene terephthalate substrate, and apply pressure on the surface of the polydimethylsiloxane film. After 5 minutes, remove the polydimethylsiloxane film to obtain Ta 2 PtSe 7 Single crystal film;

[0047] S4. Use a spin coater to spin coat photoresist on the Ta 2 PtSe 7 Single crystal film. After laser direct writing, exposure and development, a sample covered with an electrode pattern of Ta 2 PtSe 7 is obtained. Then use electron beam evaporation to deposit a titanium-gold composite film at the pattern position. Among them, the thickness of the titanium layer is 9 nm, and the thickness of the gold layer is 66 nm, thus obtaining a 10.6 μm flexible photodetector based on the new Ta 2 PtSe 7 alloy.

[0048] Example 3: Preparation of a 10.6 μm flexible photodetector based on a new Ta 2 PtSe 7 alloy, including the following steps:

[0049] S1. Weigh 0.326 g of tantalum metal, 0.175 g of platinum metal and 0.500 g of selenium metal respectively (the molar ratio of tantalum metal, platinum metal and selenium metal is 2:1:7). After mixing evenly, place them in a mortar and grind for 7 minutes. Then use a tablet press mold with a diameter of 10 mm to press the tablets, and set the pressure during tablet pressing to 60 MPa and the tablet pressing time to 37 s to obtain substance A;

[0050] S2. Place substance A in a quartz tube with an outer diameter of 13 mm, and use a mechanical pump and a molecular pump set to reduce the vacuum degree in the tube to 9×10 -6 Torr. Then seal the quartz tube with a hydrogen-oxygen mixed gas, and set the temperature to 1900 °C. After the quartz tube cools down, place it in a muffle furnace, set the temperature to 720 °C and keep it warm for 29 days to obtain Ta2 PtSe 7 Single crystal;

[0051] S3. Place Ta 2 PtSe 7 After mechanically exfoliating the single crystal on Scotch tape, stick the polydimethylsiloxane film onto the tape Ta 2 PtSe 7 At the position with more crystal flakes, use a cotton swab to squeeze to ensure that the polydimethylsiloxane film is in full contact with Ta 2 PtSe 7 The crystal flakes. After 7 minutes, separate the polydimethylsiloxane film from the tape, then stick the polydimethylsiloxane film onto the flexible polyethylene terephthalate substrate, and apply pressure on the surface of the polydimethylsiloxane film. After 5 minutes, remove the polydimethylsiloxane film to obtain Ta 2 PtSe 7 Single crystal film;

[0052] S4. Spin-coat photoresist on the Ta 2 PtSe 7 Single crystal film using a spin coater, and then obtain a sample covered with an electrode pattern after laser direct writing, exposure and development of Ta 2 PtSe 7 Then deposit a titanium-gold composite film at the pattern position by electron beam evaporation. Among them, the thickness of the titanium layer is 9 nm and the thickness of the gold layer is 67 nm, thus obtaining a 10.6 μm flexible photodetector based on the new Ta 2 PtSe 7 Alloy.

[0053] Example 4: Preparation of a 10.6 μm flexible photodetector based on a new Ta 2 PtSe 7 Alloy, including the following steps:

[0054] S1. Weigh 0.326 g of tantalum metal, 0.175 g of platinum metal and 0.500 g of selenium metal respectively (the molar ratio of tantalum metal, platinum metal and selenium metal is 2:1:7). After mixing evenly, place them in a mortar and grind for 8 minutes, then use a tablet press mold with a diameter of 10 mm for tableting, and set the pressure during tableting to 61 MPa and the tableting time to 38 s to obtain substance A;

[0055] S2. Place substance A in a quartz tube with an outer diameter of 13 mm, and use a mechanical pump and a molecular pump set to reduce the vacuum degree in the tube to 9×10 -6 Torr, then seal the quartz tube with a hydrogen-oxygen mixture, and set the temperature to 1910 °C. After the quartz tube cools, place it in a muffle furnace, set the temperature to 725 °C and keep it warm for 29 days to obtain Ta2 PtS 7 Single crystal;

[0056] S3. 2 PtS 7 After the single crystal is placed on Scotch tape for mechanical peeling, the polydimethylsiloxane film is attached to the tape. 2 PtS 7 Use a cotton swab to squeeze the area where there are more crystal flakes to ensure that the polydimethylsiloxane film is close to the Ta 2 PtS 7 The crystal slices were fully in contact. After 8 minutes, the polydimethylsiloxane film was separated from the tape, and then the polydimethylsiloxane film was attached to a flexible polyethylene terephthalate substrate. Pressure was applied to the surface of the polydimethylsiloxane film. After 6 minutes, the polydimethylsiloxane film was removed to obtain Ta. 2 PtS 7 Single crystal thin film;

[0057] S4. Put Ta 2 PtS 7 The single crystal film is spin-coated with photoresist using a coating machine, and then directly written by laser, exposed and developed to obtain a Ta film covered with electrode patterns. 2 PtS 7 The sample was then deposited with a titanium-gold composite film at the pattern position using electron beam evaporation, wherein the thickness of the titanium layer was 10 nm and the thickness of the gold layer was 69 nm. 2 PtS 7 10.6μm flexible photodetector based on alloy.

[0058] Example 5: A novel Ta-based 2 PtS 7 The preparation of the 10.6 μm flexible photodetector of the alloy includes the following steps:

[0059] S1. Weigh 0.326 g of tantalum, 0.175 g of platinum and 0.500 g of selenium (the molar ratio of tantalum, platinum and selenium is 2:1:7) respectively, mix them evenly and grind them in a mortar for 9 minutes, and then use a tableting mold with a diameter of 10 mm to compress them, and set the tableting pressure to 63 MPa and the tableting time to 39 seconds to obtain substance A;

[0060] S2. Place substance A in a quartz tube with an outer diameter of 13 mm and use a mechanical pump and a molecular pump to reduce the vacuum degree in the tube to 9×10 -6 Torr, and then seal the quartz tube with hydrogen and oxygen mixture and set the temperature to 1930℃. After the quartz tube is cooled, place it in a muffle furnace and set the temperature to 730℃ and keep it warm for 30 days to obtain Ta2 PtS 7 Single crystal;

[0061] S3. 2 PtS 7 After the single crystal is placed on Scotch tape for mechanical peeling, the polydimethylsiloxane film is attached to the tape. 2 PtS 7 Use a cotton swab to squeeze the area where there are more crystal flakes to ensure that the polydimethylsiloxane film is close to the Ta 2 PtS 7 The crystal slices were fully in contact. After 9 minutes, the polydimethylsiloxane film was separated from the tape, and then the polydimethylsiloxane film was attached to a flexible polyethylene terephthalate substrate. Pressure was applied to the surface of the polydimethylsiloxane film. After 7 minutes, the polydimethylsiloxane film was removed to obtain Ta. 2 PtS 7 Single crystal thin film;

[0062] S4. Put Ta 2 PtS 7 The single crystal film is spin-coated with photoresist using a coating machine, and then directly written by laser, exposed and developed to obtain a Ta film covered with electrode patterns. 2 PtS 7 The sample was then deposited with a titanium-gold composite film at the pattern position using electron beam evaporation, wherein the thickness of the titanium layer was 11 nm and the thickness of the gold layer was 71 nm. 2 PtS 7 10.6μm flexible photodetector based on alloy.

[0063] Example 6: A novel Ta-based 2 PtS 7 The preparation of the 10.6 μm flexible photodetector of the alloy includes the following steps:

[0064] S1. Weigh 0.326 g of tantalum, 0.175 g of platinum and 0.500 g of selenium (the molar ratio of tantalum, platinum and selenium is 2:1:7) respectively, mix them evenly and grind them in a mortar for 10 min, and then use a tableting mold with a diameter of 10 mm to tablet, and set the tableting pressure to 65 MPa and the tableting time to 40 s to obtain substance A;

[0065] S2. Place substance A in a quartz tube with an outer diameter of 13 mm and use a mechanical pump and a molecular pump to reduce the vacuum degree in the tube to 9×10 -6 Torr, and then seal the quartz tube with hydrogen and oxygen mixture and set the temperature to 1930℃. After the quartz tube is cooled, place it in a muffle furnace and set the temperature to 740℃ and keep it warm for 30 days to obtain Ta2 PtSe 7 Single crystal;

[0066] S3. Place Ta 2 PtSe 7 The single crystal on Scotch tape for mechanical exfoliation, and then stick the polydimethylsiloxane film to the tape at the position where there are more Ta 2 PtSe 7 crystal flakes. Use a cotton swab to squeeze to ensure full contact between the polydimethylsiloxane film and Ta 2 PtSe 7 crystal flakes. After 9 minutes, separate the polydimethylsiloxane film from the tape, then stick the polydimethylsiloxane film to the flexible polyethylene terephthalate substrate, and apply pressure on the surface of the polydimethylsiloxane film. After 7 minutes, remove the polydimethylsiloxane film to obtain Ta 2 PtSe 7 single crystal film;

[0067] S4. Spin-coat photoresist on the Ta 2 PtSe 7 single crystal film using a spin coater, and then obtain a sample covered with an electrode pattern after laser direct writing, exposure and development of Ta 2 PtSe 7 . Then deposit a titanium-gold composite film at the pattern position by electron beam evaporation. Among them, the thickness of the titanium layer is 12 nm and the thickness of the gold layer is 73 nm to obtain a 10.6 μm flexible photodetector based on the novel Ta 2 PtSe 7 alloy.

[0068] Performance test:

[0069] Ta 2 PtSe 7 Single crystal performance test:

[0070] Grind the Ta 2 PtSe 7 single crystal prepared in the present invention sufficiently, and obtain an X-ray scan pattern using X-ray diffraction analysis. As Figure 2 shown, where the upper black curve is the actual pattern and the lower blue curve is the theoretical pattern of Ta 2 PtSe 7 powder. It can be seen from the figure that the coincidence degree of the two is relatively high, which can prove that the Ta 2 PtSe 7 prepared in the present invention has high purity and high crystal quality; while Figure 3 of Ta 2 PtSe 7The obvious layered structure is shown in the SEM image of the single crystal. Figure 4 and Figure 5 Ta 2 PtSe 7 The point scanning energy spectrum and surface scanning spectrum of the single crystal prove that the single crystal prepared in the present invention has the same elemental ratio as the required single crystal and the elements are evenly distributed.

[0071] Put the Ta 2 PtSe 7 single crystal on the Scotch tape for mechanical exfoliation. It can be found that due to the weak van der Waals force between the layers in Ta 2 PtSe 7 , it is very easy to dissociate. Stick the silicon wafer to the position of the sample on the tape and gently remove the tape. Rod-shaped Ta 2 PtSe 7 samples with a length of dozens of microns can be observed under an optical microscope. From Figure 6 it can be seen that the Ta 2 PtSe 7 sample after exfoliation has an atomically flat and clean surface.

[0072] Optoelectronic performance test of the flexible optoelectronic detector:

[0073] Connect the Ta 2 PtSe 7 flexible device prepared in the present invention to the PCB board using conductive silver paste (SPI 05001-AB) and high-purity gold wire, and perform electrical tests on it using an FS-Pro semiconductor analyzer. Its I-V curve is as shown in Figure 8 (a). The source-drain voltage and source-drain current curve show a good linear relationship, which indicates its metallic properties and good contact with the metal electrodes during device fabrication. As shown in Figure 8 (b), align the Ta 2 PtSe 7 flexible device to the center of the 10.6μm carbon dioxide laser spot (the laser spot is 3×10 -2 cm 2 in size, which is much larger than the channel area of 9×10 -8 cm 2 ), use a photoelectric gate to switch the laser, and perform the optoelectronic detection test.

[0074] Apply a 0.1v excitation voltage to the source-drain electrodes of the device. The test of different laser power densities and photocurrents in the 10.6μm band is as shown in Figure 8 (c). As the laser power density increases (0.67 - 2W / cm 2) The photocurrent increased from 6 nA to 30 nA; its photocurrent test showed an obvious photothermal electric effect (Seebeck effect). Subsequently, lasers from visible to near-infrared and then to mid-infrared (671 nm, 1064 nm, 10.6 μm) were used to irradiate Ta 2 PtSe 7 The optoelectronic properties of the flexible device were comprehensively evaluated. Its response speeds were 2.9 s, 3.4 s, and 4.6 s respectively, as shown in Figure 8 (d); The functional relationship between its photocurrent and the power density of the externally applied excitation laser is shown in Figure 8 (e). The fitted coefficient (α) is greater than 1, which is the combined effect of various factors such as the significance of the carrier temperature gradient, the difference in thermoelectric potential, the complexity of carrier transport characteristics, and the carrier dynamics under non-equilibrium conditions; Its responsivity and the power density of the externally applied excitation laser also increase with the increase of power, as shown in Figure 8 (f), which is also an important feature of the thermoelectric effect;

[0075] Stability test:

[0076] The prepared Ta 2 PtSe 7 in the present invention was tested by Raman spectroscopy. It was exposed to air for one year. After being placed for one year, the Ta 2 PtSe 7 sample did not show obvious changes in the optical microscope, and its Raman spectrum was also basically the same as the initial one, as shown in Figure 9 Ta 2 PtSe 7 exhibits excellent air stability, which lays a solid foundation for its performance in later applications. In the field of wearable technology, the durability and reliability of devices are key considerations, and this property of Ta 2 PtSe 7 meets these requirements;

[0077] Flexibility test:

[0078] The prepared Ta 2 PtSe 7 flexible device in the present invention can complete simple flexible wearable bending, as shown in Figure 10 (a); The bending test was carried out by a high-precision vernier caliper. The calculation method of the bending radius during the bending process is shown in Figure 10 (b); During the repeated bending test with a radius of 0.2 mm, the Ta 2 PtSe 7 flexible device did not show obvious degradation during 10.6 μm optoelectronic detection, indicating its good mechanical properties and anti-fatigue characteristics.

[0079] Those of ordinary skill in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the present invention is limited to these examples; within the concept of the present invention, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present invention as described above, which are not provided in detail for the sake of brevity.

[0080] The present invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. Preparation of a 10.6μm flexible photodetector based on a new Ta2PtSe7 alloy, characterized in that: The following steps are involved: Step A1. Place the Ta2PtSe7 single crystal on a Scotch tape for mechanical peeling, then stick a polydimethylsiloxane film to the position of the tape where there are more Ta2PtSe7 crystal flakes, and use a cotton swab to squeeze to ensure that the polydimethylsiloxane film is in full contact with the Ta2PtSe7 crystal flakes. After 6-9 minutes, separate the polydimethylsiloxane film from the tape, and then stick the polydimethylsiloxane film to a flexible substrate, and apply pressure on the surface of the polydimethylsiloxane film. After 4-7 minutes, remove the polydimethylsiloxane film to obtain a Ta2PtSe7 single crystal film; Step A2. Spin-coat the Ta2PtSe7 single crystal film with photoresist using a coating machine, and then obtain a Ta2PtSe7 sample covered with an electrode pattern after laser direct writing, exposure and development. Then use electron beam evaporation to deposit a titanium-gold composite film at the pattern position to obtain a 10.6μm flexible photodetector based on the new Ta2PtSe7 alloy.

2. The preparation of a 10.6 μm flexible photodetector based on a novel Ta2PtSe7 alloy according to claim 1, characterized in that: The preparation method of the Ta2PtSe7 single crystal in step A1 is as follows: Step B1. Weigh tantalum, platinum and selenium respectively, mix them evenly, grind them in a mortar for 5-10 minutes, and then use a tableting mold with a diameter of 10 mm to tablet to obtain substance A; Step B2. Place substance A in a quartz tube with an outer diameter of 13 mm, and use a mechanical pump and a molecular pump group to reduce the vacuum degree in the tube to V1, then seal the quartz tube with a hydrogen and oxygen mixture, and set the temperature to T1. After the quartz tube is cooled, place it in a muffle furnace, set the temperature to T2 and keep it warm for 28-30 days to obtain a Ta2PtSe7 single crystal.

3. The preparation of a 10.6 μm flexible photodetector based on a novel Ta2PtSe7 alloy according to claim 2, characterized in that: The molar ratio of tantalum, platinum and selenium in step B1 is 2:1:7; The tableting pressure is 58-65 MPa and the tableting time is 35-40 s.

4. The preparation of a 10.6 μm flexible photodetector based on a novel Ta2PtSe7 alloy according to claim 2, characterized in that: V1<10 in step B2 -5 Torr; The temperature T1 is 1880-1930°C; The temperature T2 is 700-740°C.

5. The preparation of a 10.6 μm flexible photodetector based on a novel Ta2PtSe7 alloy according to claim 1, characterized in that: The flexible substrate in step A1 is polyethylene terephthalate.

6. The preparation of a 10.6 μm flexible photodetector based on a novel Ta2PtSe7 alloy according to claim 1, characterized in that: In the titanium-gold composite film described in step A2, the thickness of the titanium layer is 8-12 nm, and the thickness of the gold layer is 65-73 nm.

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