Performance test method of two-dimensional GeSe thin film and preparation method of two-dimensional GeSe thin film

Abstract

The invention provides a performance testing method of a two-dimensional GeSe thin film and a preparation method of the two-dimensional GeSe thin film, and belongs to the technical field of photoelectric materials. The method comprises the following steps: preparing a two-dimensional GeSe thin film for different types of substrates by adopting a physical vapor deposition method, and preparing an electrode on the two-dimensional GeSe thin film to construct a to-be-tested sample; testing a pre-constructed standardized index on each to-be-tested sample, and determining performance test results corresponding to different types of substrates on the basis; wherein the standardized indexes can comprise composition and structural characterization, photoelectric response parameters, first principle calculation results and the like. According to the scheme, the performance test results of the two-dimensional GeSe thin films prepared on different types of substrates by adopting the physical vapor deposition method can be obtained based on the standardized indexes, the influence mechanism of multiple types of substrates on the performance of the two-dimensional GeSe thin films is comprehensively and accurately explored through the standardized indexes, and the characteristics of the two-dimensional GeSe thin films can be fully excavated; therefore, substrate selection in a two-dimensional GeSe thin film preparation process is accurately and efficiently guided.

Description

Technical Field

[0001] The present disclosure relates to the technical field of optoelectronic materials, and in particular to a performance testing method for a two-dimensional GeSe thin film and a method for preparing a two-dimensional GeSe thin film. Background Art

[0002] GeSe is a binary semiconductor material with significant structural anisotropy, excellent environmental stability, and a high-energy-density spectroscopy (EMS) range from the near-infrared to ultraviolet (NIR-UV) region up to 105 cm -1 The broad optical absorption coefficient, band gap of about 1.14 eV and the optical absorption of about 128.6 cm 2 V -1 s -1 It has high carrier mobility and other characteristics. It shows great application potential in optoelectronic devices such as photodetectors, field-effect transistors, and solar cells.

[0003] The optoelectronic properties of two-dimensional GeSe thin films are influenced by a variety of factors. While factors such as film thickness, crystal structure, and defect density have been extensively studied, the fabrication of two-dimensional GeSe thin films on substrates and the mechanisms that influence their optoelectronic properties remain understudied.

[0004] The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Summary of the Invention

[0005] The purpose of the present disclosure is to provide a performance testing method for a two-dimensional GeSe thin film and a two-dimensional GeSe thin film preparation method, which can obtain performance test results based on standardized indicators for two-dimensional GeSe thin films prepared by physical vapor deposition on different types of substrates. Through standardized indicators, the influence mechanism of multiple types of substrates on the performance of two-dimensional GeSe thin films is comprehensively and accurately explored, and the characteristics of two-dimensional GeSe thin films are fully explored, so as to accurately and efficiently guide the selection of substrates in the preparation process of two-dimensional GeSe thin films under different application requirements.

[0006] To achieve the above-mentioned purpose, the present invention adopts the following technical solutions: According to the first aspect of the present disclosure, a performance testing method for a two-dimensional GeSe film is provided, which may include: selecting at least two different types of substrates; preparing a two-dimensional GeSe film by physical vapor deposition on each substrate, and preparing electrodes on the two-dimensional GeSe film to obtain test samples corresponding to different types of substrates; testing pre-constructed standardized indicators on each test sample; the standardized indicators include at least one of composition and structure characterization, photoelectric response parameters, and first-principles calculation results; based on the standardized indicators of the test samples, determining the performance test results corresponding to different types of substrates.

[0007] According to a second aspect of the present disclosure, a method for preparing a two-dimensional GeSe thin film is provided, which may include: obtaining application performance requirements of the two-dimensional GeSe thin film; matching performance test results corresponding to different types of substrates based on the application performance requirements, the performance test results being obtained by testing the performance test method for the two-dimensional GeSe thin film of the first aspect; and using physical vapor deposition to prepare a two-dimensional GeSe thin film on a substrate whose performance test results match the application performance requirements.

[0008] The performance testing method of the two-dimensional GeSe film provided by the present disclosure uses physical vapor deposition to prepare two-dimensional GeSe films on different types of substrates, and prepares electrodes on the two-dimensional GeSe films to construct test samples; pre-constructed standardized indicators are tested on each test sample, and on this basis, the performance test results corresponding to different types of substrates are determined; wherein, the standardized indicators may include composition and structure characterization, photoelectric response parameters, and first-principles calculation results. This scheme can obtain performance test results based on standardized indicators for two-dimensional GeSe films prepared by physical vapor deposition on different types of substrates. Through standardized indicators, the mechanism of the influence of multiple types of substrates on the performance of two-dimensional GeSe films can be comprehensively and accurately explored, which can fully explore the characteristics of two-dimensional GeSe films, thereby accurately and efficiently guiding the selection of substrates in the preparation process of two-dimensional GeSe films under different application requirements.

[0009] The disclosed method for preparing a two-dimensional GeSe thin film can determine application performance requirements when preparing the two-dimensional GeSe thin film, match the application performance requirements with performance test results corresponding to different types of substrates, and use physical vapor deposition to prepare the two-dimensional GeSe thin film on a substrate whose performance test results match the application performance requirements; wherein the performance test results are based on the aforementioned performance test method for two-dimensional GeSe thin films. This solution can combine actual application performance requirements with performance test results to match and select appropriate substrates when preparing two-dimensional GeSe thin films, thereby enabling flexible and targeted preparation of two-dimensional GeSe thin films that meet application requirements in different environments, further fully and deeply exploring the application potential of two-dimensional GeSe. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the following briefly introduces the drawings required for use in the embodiments or the conventional technology descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0011] Figure 1 A flow chart showing the steps of a performance testing method for a two-dimensional GeSe film in an embodiment of the present disclosure is shown.

[0012] Figure 2 A process flow chart for preparing a two-dimensional GeSe thin film using physical vapor deposition in an embodiment of the present disclosure is shown.

[0013] Figure 3 Schematic diagram of XRD of a two-dimensional GeSe film on a ceramic wafer, a glass slide, and an oxide-layer silicon wafer in an embodiment of the present disclosure is shown.

[0014] Figure 4 A schematic diagram of the magnified XRD (111) and (400) diffraction peaks of a two-dimensional GeSe film on a ceramic wafer, a glass slide, and an oxide-layer silicon wafer in an embodiment of the present disclosure is shown.

[0015] Figure 5 Schematic diagram of Raman spectra of a two-dimensional GeSe film on a ceramic wafer, a glass slide, and an oxide-layer silicon wafer in an embodiment of the present disclosure is shown.

[0016] Figure 6 Scanning electron microscope images of a two-dimensional GeSe thin film on a ceramic wafer, a glass slide, and an oxide-layer silicon wafer according to an embodiment of the present disclosure are shown.

[0017] Figure 7 The diffuse reflectance spectrum of a two-dimensional GeSe thin film grown on a ceramic wafer according to an embodiment of the present disclosure is shown.

[0018] Figure 8 1 shows the optical band gap diagram of a two-dimensional GeSe thin film grown on a ceramic wafer according to an embodiment of the present disclosure.

[0019] Figure 9 The diffuse reflectance spectrum of a two-dimensional GeSe thin film grown on a glass slide according to an embodiment of the present disclosure is shown.

[0020] Figure 10 Graph showing the optical band gap of a two-dimensional GeSe thin film grown on a glass slide according to an embodiment of the present disclosure.

[0021] Figure 11The diffuse reflectance spectrum of a two-dimensional GeSe thin film grown on an oxide-layer silicon wafer according to an embodiment of the present disclosure is shown.

[0022] Figure 12 The optical band gap diagram of a two-dimensional GeSe thin film grown on an oxide-layer silicon wafer according to an embodiment of the present disclosure is shown.

[0023] Figure 13 The current-voltage curves of a two-dimensional GeSe thin film grown on a ceramic wafer in an embodiment of the present disclosure are shown at no light, 365 nm, 530 nm, 660 nm, and 880 nm.

[0024] Figure 14 1 shows the current-time curve of a two-dimensional GeSe thin film grown on a ceramic wafer at 100% power in an embodiment of the present disclosure.

[0025] Figure 15 The current-voltage curves of a two-dimensional GeSe thin film grown on a glass slide in an embodiment of the present disclosure are shown at no light, 365 nm, 530 nm, 660 nm, and 880 nm.

[0026] Figure 16 1 shows the current-time curve of a two-dimensional GeSe thin film grown on a glass slide at 100% power in an embodiment of the present disclosure.

[0027] Figure 17 The current-voltage curves of a two-dimensional GeSe thin film grown on an oxide-layer silicon wafer in an embodiment of the present disclosure are shown at no light, 365 nm, 530 nm, 660 nm, and 880 nm.

[0028] Figure 18 The current-time curve of a two-dimensional GeSe film grown on an oxide-layer silicon wafer under 100% power in an embodiment of the present disclosure is shown.

[0029] Figure 19 1 and 2. Shown are a top view and a side view of a two-dimensional GeSe thin film model according to an embodiment of the present disclosure.

[0030] Figure 20 A schematic diagram of the partial-wave density of states of a two-dimensional GeSe film in an embodiment of the present disclosure is shown.

[0031] Figure 21 A flow chart showing the steps of a method for preparing a two-dimensional GeSe thin film in an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0032] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be more comprehensive and complete and will fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to provide a thorough understanding of the embodiments of the present disclosure.

[0033] The described features, structures or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure can be practiced without one or more of the specific details, or other methods, components, materials, etc. can be adopted. In other cases, well-known structures, materials or operations are not shown or described in detail to avoid obscuring the main technical ideas of the present disclosure.

[0034] When a structure is “on” another structure, it may mean that the structure is integrally formed on the other structure, or that the structure is “directly” disposed on the other structure, or that the structure is “indirectly” disposed on the other structure via another structure.

[0035] The terms "a," "an," and "the" are used to indicate the presence of one or more elements / components; the terms "including" and "having" are used to indicate an open-ended inclusiveness and mean that additional elements / components / etc. may be present in addition to the listed elements / components / etc. The terms "first," "second," etc. are used merely as labels and do not limit the quantity of the items to which they refer.

[0036] It should be noted that the two-dimensional GeSe thin film disclosed herein is also referred to as GeSe thin film for short.

[0037] Figure 1 FIG. 4 shows a flow chart of the steps of the performance testing method of the two-dimensional GeSe film according to the embodiment of the present disclosure. Figure 1 As shown, the method may include steps 101 to 104. As shown below: Step 101: Select at least two different types of substrates.

[0038] In the disclosed embodiments, performance testing can be performed on two-dimensional GeSe thin films produced using physical vapor deposition on substrates. Different substrate types can be selected for performance testing, encompassing a wide range of application environments and currently used or researched process conditions, enabling comprehensive evaluation of the mechanisms by which substrates affect the performance of two-dimensional GeSe thin films.

[0039] In an optional embodiment of the present disclosure, the types of the substrate may include a transparent substrate and a non-transparent substrate.

[0040] In the disclosed embodiments, substrates can be classified into transparent and non-transparent types based on their transparency. When selecting a substrate, at least two different types of substrates can be selected. This can include at least two types of transparent substrates, at least two types of non-transparent substrates, or a combination of transparent and non-transparent substrates. Transparent and non-transparent substrates have different levels of transparency, allowing for multiple substrate types to be selected based on actual needs.

[0041] In an optional embodiment of the present disclosure, the transparent substrate may include a glass slide.

[0042] In an optional embodiment of the present disclosure, the non-transparent substrate may include a ceramic wafer and an oxide layer silicon wafer.

[0043] In the embodiments of the present disclosure, the transparent substrate may include a glass slide, which is transparent; the non-transparent substrate may include a ceramic sheet and an oxide-layer silicon wafer, which is not transparent. When selecting a substrate, at least two of the glass slide, ceramic sheet, and oxide-layer silicon wafer may be selected. Those skilled in the art may also classify other substrate types according to actual needs, and select other substrates for the preparation and performance testing of two-dimensional GeSe thin films, and the embodiments of the present disclosure do not impose specific restrictions on this.

[0044] Step 102 : Prepare a two-dimensional GeSe thin film on each substrate using a physical vapor deposition method, and prepare an electrode on the two-dimensional GeSe thin film to obtain test samples corresponding to different types of substrates.

[0045] In the embodiment of the present disclosure, a two-dimensional GeSe thin film can be prepared on each selected substrate using a physical vapor deposition (PVD) method. The physical vapor deposition method can cause the raw materials in the reactor to evaporate thermally at high temperature under vacuum conditions, so that the evaporated particles are deposited on the substrate to form a thin film. In the process of preparing a thin film using the physical vapor deposition method, the thickness of the prepared film can be controlled by controlling the input amount of the precursor. On this basis, the thickness of the prepared two-dimensional GeSe thin film can be made consistent on different types of substrates by controlling the input amount of GeSe powder, thereby avoiding the difference in film thickness on different substrates interfering with the accuracy of the performance test results.

[0046] For example, taking three types of substrates, glass slide, ceramic wafer (Al2O3), and oxide layer silicon wafer (SiO2 / Si), the process flow of preparing two-dimensional GeSe thin film by physical vapor deposition can be as follows: Figure 2 shown.

[0047] like Figure 2 As shown, 25 mg of GeSe powder (160 mesh, 99.99%) was accurately weighed into a 0.5 cm × 10 cm quartz boat and placed in the center of the quartz tube. A glass slide, ceramic wafer, and oxide-coated silicon wafer were cleaned using a mixture of CCl₄ (carbon tetrachloride) and acetone, ethanol, and deionized water in an ultrasonic cleaner for approximately 30 minutes. The cleaned substrates were placed 25.6 cm downstream of the heating zone, from the quartz boat, with a distance of approximately 4 cm between the substrate and the bottom of the quartz tube.

[0048] Furthermore, a vacuum pump is used to evacuate the inside of the quartz tube to a vacuum state, and then the quartz tube is flushed with argon (Ar) at a flow rate of 450 sccm for 10 minutes. During the flushing process, the gas flow rate is precisely controlled by a mass flow controller. While maintaining the Ar flow rate of 190 sccm, the quartz tube is heated at 560°C for 70 minutes for reaction, and the heating rate is usually 20°C / min. During the reaction, the vapor particles generated by the GeSe powder are transported to the cooler area where the substrate is located by the Ar carrier gas. At this time, the temperature range of the substrate is about 380°C, and vapor particle deposition occurs. After the reaction is completed and naturally cooled to room temperature, the substrate is taken out. At this time, a black two-dimensional GeSe film is evenly grown on the substrate, and most of the GeSe powder in the quartz boat has been consumed by the reaction, leaving only a small amount of silver-gray residue.

[0049] In the embodiments of the present disclosure, electrodes can be further prepared based on the preparation of a two-dimensional GeSe thin film. Those skilled in the art can select electrode materials, electrode layouts, and electrode preparation methods according to actual needs, and this application does not impose specific limitations on this.

[0050] For example, taking silver electrodes as an example, the electrode construction is carried out by using a dot coating method. A specific type of 3701 silver paste is applied carefully and evenly on the surface of the two-dimensional GeSe film to form an orderly arranged silver electrode array. In the silver electrode array, the spacing between adjacent electrodes is about 0.1 cm, and the effective contact area of each electrode is about 0.01 cm. 2 To maintain the consistency and reliability of electrode performance.

[0051] A two-dimensional GeSe film is prepared on a substrate, and electrodes are prepared on the two-dimensional GeSe film to obtain test samples corresponding to different types of substrates. For example, the test samples may include those corresponding to glass slides, ceramic wafers, and oxide-layer silicon wafers.

[0052] Step 103: testing pre-established standardized indicators on each sample to be tested; the standardized indicators include at least one of composition and structure characterization, photoelectric response parameters, and first-principles calculation results.

[0053] In the disclosed embodiment, the standardized index can be a standardized thin film performance evaluation index pre-constructed based on substrate type, process conditions, application requirements and other factors. The standardized index can include evaluation indicators of various aspects such as elemental composition, film structure, optoelectronic properties, etc., so as to achieve comprehensive, sufficient, unified and standardized performance testing of two-dimensional GeSe films prepared on different types of substrates. The standardized index can also be adjusted according to the working feedback of the two-dimensional GeSe film prepared on the corresponding type of substrate in the application environment, so that the test results more accurately meet the application requirements.

[0054] In the embodiment of the present disclosure, the standardized indicators may include composition and structure characterization, and one or more characterization techniques are used to test the sample morphology, chemical element composition, crystal structure and parameters, etc.

[0055] In the embodiment of the present disclosure, the standardized indicators may include photoelectric response parameters, and the photoelectric response performance of the two-dimensional GeSe thin films on different types of substrates is tested by irradiating them with light sources of different wavelengths.

[0056] In the disclosed embodiment, the standardized index may include the results of first-principles calculations. First-principles refers to the use of seven physical constants, namely the speed of light, Planck constant, atomic structure constant, electron mass, electron charge, nuclear mass, and nuclear charge, as known parameters in material calculations. Mathematical tools are used to solve the Schrödinger equation, and the basic properties of the material in the ground state can be calculated without introducing empirical parameters. When the standardized index includes the results of first-principles calculations, the calculation can be performed by simulating the electronic structure and properties of GeSe monolayer materials.

[0057] Step 104: Based on the standardized indicators of the samples to be tested, performance test results corresponding to different types of substrates are determined.

[0058] In the embodiment of the present disclosure, after obtaining the standardized indicators of the test samples corresponding to different types of substrates, the performance test results thereof can be determined based on the standardized indicators. The performance test results can describe the meaning expressed by the standardized indicators, thereby demonstrating the mechanism of the influence of the substrate type on the two-dimensional GeSe film, such as the differences and similarities in morphology, structure, composition, photoelectric performance, etc. of the two-dimensional GeSe film based on different substrate types. On this basis, the application requirements applicable to the preparation of the two-dimensional GeSe film based on different types of substrates can be determined based on the performance test results, accurately guiding the selection of substrate types in the specific preparation process of the two-dimensional GeSe film.

[0059] In an optional embodiment of the present disclosure, the standardized indicators include composition and structure characterization, and the aforementioned step 103 includes the following step A1.

[0060] Step A1: characterize each sample to be tested by using an X-ray diffraction pattern to obtain at least one of the phase composition, crystal structure, grain size, and crystal strain of the sample to be tested.

[0061] In the embodiment of the present disclosure, when the standardized indicators include composition and structure characterization, an XRD (X-ray Diffraction) spectrum can be used to generate diffraction peaks through the interaction of X-rays with the two-dimensional GeSe thin film on the test sample, thereby analyzing the phase composition, crystal structure, etc. of the two-dimensional GeSe thin film on the test sample based on the diffraction peaks, and further calculating the grain size and crystal strain, etc.

[0062] Exemplarily, the test sample corresponding to the glass slide, the test sample corresponding to the ceramic wafer, and the test sample corresponding to the oxide layer silicon wafer are characterized by using XRD patterns. Figure 3 Schematic diagram of XRD of two-dimensional GeSe thin film on ceramic chip (Al2O3), slide and oxide layer silicon wafer (SiO2 / Si) in the embodiment of the present disclosure, and Figure 4 Schematic diagram of the magnified XRD (111) and (400) diffraction peaks of the two-dimensional GeSe film on a ceramic wafer, a glass slide, and an oxide-layer silicon wafer in the embodiment of the present disclosure, where the ordinate is intensity and the abscissa is angle.

[0063] GeSe thin films show specific diffraction peaks in the XRD spectrum, among which the diffraction peaks of (111) and (400) crystal planes are the most significant in intensity. Figure 3 As shown in the figure, referring to the JCPDS (Joint Committee on Powder Diffraction Standards) card, the characteristic diffraction peaks of the GeSe structure shown in JCPDS NO.48-1226 are marked with red dots, and the characteristic peaks corresponding to the Al2O3 ceramic piece shown in JCPDS NO.46-1212 are marked with blue asterisks. Among them, the two significant characteristic peaks at 32.18° and 33.24° correspond to the GeSe (111) and (400) crystal plane diffraction peaks, respectively.

[0064] No impurity peaks were detected in the XRD patterns, indicating that the 2D GeSe films grown on different substrate types are composed of pure GeSe. The differences in XRD patterns also indicate that the crystal structure and quality of 2D GeSe films are significantly affected by the substrate type, likely due to factors such as the substrate's lattice matching, surface energy, and thermal expansion coefficient.

[0065] Furthermore, the following Debye-Scherrer formula (1) can be used to calculate the grain size (d (111) ) and (d (400) ): (1) Where, β is the half-height width (FWHM) of the diffraction peak, converted into radians ( β ÷180)×3.14, is the Bragg diffraction angle of GeSe, in degrees (°), Cu by XRD The diffraction wavelength (1.54056Å) and the grain sizes corresponding to the (111) and (400) diffraction peaks of GeSe films grown on different types of substrates are shown in Table 1 below: Table 1 Grain size of GeSe films grown on different substrates

[0066] From the aforementioned Figure 3 As can be seen from Table 1 above, among different types of substrates, the two-dimensional GeSe film on the oxide silicon wafer exhibits the strongest diffraction peak, and the half-height width of the diffraction peak of the (111) and (400) crystal phases is relatively the smallest, and the grain size is relatively the largest, indicating that the prepared two-dimensional GeSe film has the best crystal quality; the (111) diffraction peak intensity of the two-dimensional GeSe film grown on the ceramic wafer is second, and the grain size is small, so the crystal quality is second; while the (111) diffraction peak of the GeSe film grown on the glass slide is the weakest, and the grain size is relatively the smallest, indicating that the crystal quality is relatively the lowest. It can be seen that the stronger the (111) diffraction peak of the two-dimensional GeSe film is, the more it tends to grow in the preferred orientation along the (111) crystal plane. In general, based on the demand for crystal quality, oxide silicon wafers, ceramic wafers and glass slides can be selected from high to low.

[0067] like Figure 4 The enlarged images of the (111) and (400) diffraction peaks of GeSe films grown on different types of substrates are shown. It can be seen that the (111) and (400) diffraction peaks of the two-dimensional GeSe film grown on the glass slide are both shifted to low angles by about 0.03°, indicating that there is distortion or stress in the lattice of the GeSe film grown on the glass slide.

[0068] Furthermore, the strain (ε) corresponding to the (111) and (400) crystal planes of GeSe films can be calculated using the following lattice strain formula (2): (111) ) and (ε (400) ): ε=(d-d0) / d0(2) Among them, d is the actual lattice spacing of the sample to be tested, and d0 is the lattice spacing of the standard card spectrum sample.

[0069] For thin film materials, when d < d0, it indicates compressive stress (ε < 0); when d > d0, it indicates tensile stress (ε > 0). Taking the standard GeSe sample as an example, the lattice plane spacing d of its (111) crystal plane (111) is 2.7900, and the lattice plane spacing d of its (400) crystal plane (400) is 2.7100. In the embodiments of the present disclosure, by measuring the lattice plane spacings d corresponding to the (111) and (400) diffraction peaks of the two-dimensional GeSe thin film grown on different types of substrates (111) and d (400) , the corresponding strains ε (111) , ε (400) can be calculated respectively. The specific data are shown in Table 2 below.

[0070] Table 2 Lattice Strains of Two-Dimensional GeSe Thin Films Grown on Different Types of Substrates

[0071] As can be seen from Table 2 above glass slide > ceramic sheet > silicon wafer with oxide layer, and glass slide > ceramic sheet > silicon wafer with oxide layer. When calculating stress using XRD data, it usually involves changes in lattice spacing. The existence of stress will cause lattice distortion, which in turn causes the shift of diffraction peaks. By analyzing the data in Table 2 above, it is determined that there is a situation where d < d0, indicating that there is compressive stress between the lattices of the GeSe thin film.

[0072] On this basis, combining the foregoing Figure 4 and the data in Table 2 above, it can be seen that the XRD diffraction peak positions of the GeSe thin film grown on the silicon wafer with oxide layer basically do not change, and the strains (ε (111) ) and (ε (400) ) corresponding to the (111) and (400) crystal planes have relatively the smallest values; the diffraction peak positions of the GeSe thin film grown on the ceramic sheet basically do not change, and the strains (ε (111) ) and (ε (400) ) corresponding to the (111) and (400) crystal planes have relatively smaller values; the diffraction peak positions of the GeSe thin film grown on the glass slide have a large shift, and the strains (ε (111) ) and (ε (400)) has the largest value. The above data indicate that the internal stress of the two-dimensional GeSe film is relatively minimal and of relatively highest quality on the oxide silicon wafer, relatively second and of relatively higher quality on the ceramic wafer, and relatively largest and of relatively lower quality on the glass slide. This indicates that there is a relatively best lattice match between the oxide silicon wafer and GeSe, and the oxide silicon wafer is a single crystal substrate, which can promote the growth of the GeSe film along a specific (111) crystal plane to form an ordered crystal structure. The ceramic wafer has a smaller lattice mismatch with the GeSe film interface, while the glass slide has a larger lattice mismatch with the GeSe film interface, resulting in significant lattice distortion at the interface.

[0073] In an optional embodiment of the present disclosure, the standardized indicators include composition and structure characterization, and the aforementioned step 103 includes the following step A2.

[0074] Step A2: characterize each sample to be tested using Raman spectroscopy, and analyze the material composition of the sample to be tested based on the molecular vibration mode.

[0075] In the disclosed embodiment, when the standardized indicators include composition and structure characterization, Raman spectroscopy can be used to analyze the molecular vibration mode of the two-dimensional GeSe film on the test sample to identify the material composition, and the influence mechanism of the substrate type on the two-dimensional GeSe film can be evaluated based on information such as peak intensity and peak position.

[0076] For example, Raman spectroscopy is used to characterize the test sample corresponding to the glass slide, the test sample corresponding to the ceramic wafer, and the test sample corresponding to the oxide layer silicon wafer. Figure 5 Schematic diagram of Raman spectra of two-dimensional GeSe thin films on ceramic wafers, glass slides and oxide-layer silicon wafers in the embodiment of the present disclosure, where the ordinate is intensity and the abscissa is Raman shift. Raman shift is expressed in wavenumbers (cm -1 ) quantitatively characterize molecular structure information.

[0077] According to the symmetry principle of the D2h16 group, GeSe theoretically has 12 Raman active vibration modes, including 4 A g Mode, 2 B 1g Mode, 4 B 2g Mode and 2 B 3g mode. Figure 5 Three main vibration modes were observed in the Raman spectrum shown, namely, -1 A g3 Mode, located at 150cm -1 B 3g Mode, and located at 188cm -1 A g1The above molecular vibration modes are highly consistent with the standard, confirming that the structure and composition of the two-dimensional GeSe film are in line with the preparation expectations.

[0078] On this basis, different types of substrates significantly affect the position and intensity of the peaks. The Raman peak intensity of the two-dimensional GeSe film on ceramic wafers and oxide-layer silicon wafers is higher, while the GeSe Raman signal on the glass slide is weaker. This indicates that the crystal quality of the two-dimensional GeSe film on ceramic wafers and oxide-layer silicon wafers is relatively good, and the peak position is relatively consistent with the standard GeSe data; while the crystal quality of the two-dimensional GeSe film on the glass slide is relatively low, and there may be lattice defects or insufficient thickness. In addition, the slight shift of the Raman peak caused by different types of substrates may be related to lattice stress or the interface interaction between the substrate and the film.

[0079] In an optional embodiment of the present disclosure, the standardized indicators include composition and structure characterization, and the aforementioned step 103 includes the following step A3.

[0080] Step A3: characterize each sample to be tested using a scanning electron microscope image to obtain at least one of the surface morphology and microstructure of the sample to be tested.

[0081] In the disclosed embodiments, when the standardized indicators include composition and structure characterization, scanning electron microscopy (SEM) images can be used to characterize the two-dimensional GeSe thin film produced on the test sample. SEM images are obtained by scanning with a high-energy electron beam, collecting, amplifying, and re-imaging the excited physical information, thereby characterizing the surface morphology and microstructure of the test sample.

[0082] For example, the samples to be tested corresponding to the glass slide, the samples to be tested corresponding to the ceramic wafer, and the samples to be tested corresponding to the oxide layer silicon wafer are characterized using scanning electron microscope images. Figure 6 Scanning electron microscope images of a two-dimensional GeSe thin film on a ceramic wafer, a glass slide, and an oxide-layer silicon wafer in an embodiment of the present disclosure, where (a) is a ceramic wafer, (b) is a glass slide, and (c) is an oxide-layer silicon wafer.

[0083] like Figure 6 As shown in the figure, GeSe films grown on silicon wafers with oxide layers formed the most compact nanowire arrays in the vertical direction. Two-dimensional GeSe films grown on ceramic wafers also formed a relatively compact nanowire array in the vertical direction, with relatively consistent diameters between the nanowires, but shorter than those grown on silicon wafers with oxide layers. GeSe films grown on glass slides formed vertically distributed polyhedrons. It can be seen that the morphology of the film is affected by the substrate type.

[0084] Specifically, from Figure 6It can be seen that the lattice mismatch between the GeSe film and the substrate affects the lattice stress, thereby affecting the morphology of the GeSe film. The lattice mismatch between the GeSe film and the glass slide is relatively large, resulting in disordered adsorption and growth of GeSe particles, forming the aforementioned polyhedron morphology. The lattice mismatch between the GeSe film and the ceramic wafer is relatively small, but the ceramic wafer is polycrystalline and has a relatively rough surface, resulting in uneven nanowires. The lattice mismatch between the GeSe film and the oxide-layered silicon wafer is relatively small, and the oxide-layered silicon wafer is single crystal and has a smooth surface, resulting in a uniformly distributed nanowire arrangement.

[0085] In an optional embodiment of the present disclosure, the standardized indicators include composition and structure characterization, and the aforementioned step 103 includes the following step A4.

[0086] Step A4: Characterize each sample to be tested using scanning electron microscope images combined with energy dispersive X-ray spectroscopy to obtain at least one of the elemental composition and elemental distribution of the sample to be tested.

[0087] In the disclosed embodiment, when the standardized indicators include composition and structure characterization, scanning electron microscope images and energy dispersive spectrometer (EDS) X-ray spectroscopy can be used as a supplement to characterize the elemental composition and element distribution of the two-dimensional GeSe thin film on each test sample.

[0088] For example, for the test samples corresponding to the glass slide, the test samples corresponding to the ceramic wafer, and the test samples corresponding to the oxide layer silicon wafer, SEM-EDS was used for combined analysis, and GeSe thin films prepared on different substrates were analyzed by mapping. Among them, the element distribution of the test samples corresponding to the ceramic wafer is shown in Table 3 below: Table 3

[0089] The element distribution of the test sample corresponding to the slide is shown in Table 4 below: Table 4

[0090] The element distribution of the oxide layer silicon wafer corresponding to the test sample is shown in Table 5 below: Table 5

[0091] Tables 3 to 5 show that the atomic percentages of Se in 2D GeSe films grown on ceramic, glass, and oxide-coated silicon wafers are 41.11%, 38.57%, and 41.64%, respectively, while the atomic percentages of Ge are 39.78%, 37.87%, and 41.20%. These atomic percentages of Se and Ge approach 1.03:1, 1.02:1, and 1.01:1, respectively, indicating that the elemental composition of GeSe films grown on different substrate types is consistent, and the elemental distribution exhibits a relatively balanced Ge:Se ratio.

[0092] In addition, the detected O, C, and Au elements should mainly come from environmental pollutants, substrate materials, or a gold layer sprayed on the surface to improve conductivity. No other foreign impurity elements were found, confirming the purity and consistency of the elemental composition of the film, which can be verified with other standardized indicators of composition and structure characterization, such as XRD and Raman spectroscopy.

[0093] In an optional embodiment of the present disclosure, the standardized indicators include composition and structure characterization, and the aforementioned step 103 includes the following step A5.

[0094] Step A5: characterize each sample to be tested by using X-ray photoelectron spectroscopy to obtain the GeSe fitting binding energy of the sample to be tested.

[0095] In the disclosed embodiment, when the standardized indicators include composition and structural characterization, XPS (X-ray Photoelectron Spectroscopy) can be used to detect photoelectrons excited by X-rays in the two-dimensional GeSe film on the test sample to obtain information such as the elemental composition, chemical state, and relative content of the film surface, and further determine the GeSe fitting binding energy to evaluate the purity and chemical stability of the GeSe film.

[0096] For example, the test samples corresponding to the glass slide, the test samples corresponding to the ceramic wafer, and the test samples corresponding to the oxide layer silicon wafer are characterized respectively by XPS to obtain the XPS spectra of Ge3d and Se3d, and are charge calibrated with C1s (284.8 eV) as a reference to ensure accuracy.

[0097] Among them, the XPS spectrum of GeSe thin film Ge3d grown on ceramic wafer shows that the binding energy (Binding Energy) has two characteristic peaks located at about 29.96eV and 32.00eV, respectively, corresponding to the energy levels of Ge3d5 / 2 and Ge3d3 / 2 electron orbitals in GeSe molecules; the XPS spectrum of GeSe thin film Se3d grown on ceramic wafer shows that the binding energy has two characteristic peaks located at about 53.72eV and 54.58eV, respectively, corresponding to the energy levels of Se3d5 / 2 and Se3d3 / 2 electron orbitals in GeSe molecules.

[0098] The XPS spectrum of GeSe thin film Ge3d grown on a glass slide shows that the binding energy has two characteristic peaks located at 29.95eV and 30.87eV, respectively, corresponding to the energy levels of Ge3d5 / 2 and Ge3d3 / 2 electron orbitals in GeSe molecules; the XPS spectrum of GeSe thin film Se3d grown on a glass slide shows that the binding energy has two characteristic peaks located at 53.74eV and 54.59eV, respectively, corresponding to the energy levels of Se3d5 / 2 and Se3d3 / 2 electron orbitals in GeSe molecules.

[0099] The XPS spectrum of GeSe thin film Ge3d grown on oxide layer silicon wafer shows that the binding energy has two characteristic peaks located at about 29.95eV and 32.10eV, respectively, corresponding to the energy levels of Ge3d5 / 2 and Ge3d3 / 2 electron orbits in GeSe molecules; the XPS spectrum of GeSe thin film Ge3d grown on oxide layer silicon wafer shows that the binding energy has two characteristic peaks located at 54.29eV and 55.10eV, respectively, corresponding to the Se3d5 / 2 and Se3d3 / 2 peaks of Se3d in GeSe molecules.

[0100] On this basis, the binding energy fitting analysis of Ge and Se was performed. The GeSe fitting binding energy was consistent with the standard binding energy data of GeSe, indicating that the prepared GeSe film had the desired purity and chemical stability.

[0101] In an optional embodiment of the present disclosure, the substrate is a transparent substrate, and the aforementioned step 103 includes the following step A6.

[0102] Step A6: characterize each sample to be tested using ultraviolet-visible-near infrared spectroscopy to obtain the optical properties and band gap value of the sample to be tested.

[0103] In the embodiment of the present disclosure, when the substrate type is a transparent substrate, the two-dimensional GeSe thin film prepared on the test sample can be characterized by ultraviolet-visible-near-infrared spectroscopy to obtain its absorption characteristics of ultraviolet, visible and near-infrared light sources, and the absorption spectrum is converted into a reflection spectrum using the following formula (3) to characterize its optical properties, and on this basis, its band gap value is determined.

[0104] A=log(1 / R ∞ )(3) Where A represents absorbance or light absorption; R ∞ Represents relative diffuse reflectance.

[0105] In an optional embodiment of the present disclosure, the substrate is a non-transparent substrate, and the aforementioned step 103 includes the following step A7.

[0106] Step A7: characterize each sample to be tested using diffuse reflectance spectroscopy to obtain the optical properties and band gap value of the sample to be tested.

[0107] In the embodiment of the present disclosure, when the substrate type is a non-transparent substrate, diffuse reflectance spectroscopy can be used to characterize the two-dimensional GeSe film prepared on the test sample, and its optical properties can be characterized based on its scattering and reflection of light, and its band gap value can be determined on this basis.

[0108] For example, the test samples corresponding to the glass slide are characterized by ultraviolet-visible-near infrared spectroscopy, and the test samples corresponding to the ceramic wafer and the test samples corresponding to the oxide layer silicon wafer are characterized by diffuse reflectance spectroscopy.

[0109] Figure 7 is the diffuse reflectance spectrum of the two-dimensional GeSe thin film grown on the ceramic wafer in the embodiment of the present disclosure, Figure 8 is an optical band gap diagram of a two-dimensional GeSe thin film grown on a ceramic wafer in an embodiment of the present disclosure, Figure 9 is the diffuse reflectance spectrum of the two-dimensional GeSe thin film grown on a glass slide in the embodiment of the present disclosure, Figure 10 is an optical band gap diagram of a two-dimensional GeSe thin film grown on a glass slide in an embodiment of the present disclosure, Figure 11 is the diffuse reflectance spectrum of the two-dimensional GeSe thin film grown on the oxide layer silicon wafer in the embodiment of the present disclosure, Figure 12The optical band gap diagram of the two-dimensional GeSe film grown on the oxide silicon wafer in the embodiment of the present disclosure is shown in Figure 2. The above-mentioned glass slide was analyzed using UV-Vis-NIR spectroscopy and converted according to the above formula (3); the ceramic wafer and the oxide silicon wafer were analyzed using diffuse reflectance spectroscopy with the ordinate as reflectance and the abscissa as wavelength. On this basis, the Kubelka-Munk formula (4) was used to convert Figure 7 、 9 The data of 11 is converted into the energy of the photon (Energy) on the horizontal axis and [F(R)hv] on the vertical axis. 1 / 2 of Figure 8 、 10 and the curve of 12.

[0110] (F(R)hν) 1 / 2 =(1-R) 2 / 2R=B(hν-E g )(4) Where F(R) represents the reflectance spectrum function; h is Planck's constant, ν is the frequency of light, and hν represents energy; R is the reflectivity; Eg is the band gap energy, and B is a constant related to the material absorption coefficient.

[0111] By Figure 8 、 10 And 12, the curved part on the curve is extended in the reverse direction along the tangent direction, and the intersection of the extended line and the horizontal coordinate is obtained, which is the band gap of the sample to be tested.

[0112] From the above Figures 7 to 12 Analysis shows that the GeSe film grown on a ceramic wafer has a band gap of 1.184eV, the GeSe film grown on an oxide-layer silicon wafer has a band gap of 1.031eV, and the GeSe film grown on a glass slide has a band gap of 1.662eV, indicating that they are all suitable for the absorption of the solar spectrum and near-infrared light, and are suitable for application needs in the field of visible light and near-infrared light detection.

[0113] In an optional embodiment of the present disclosure, the standardized index includes a photoelectric response parameter, and the aforementioned step 103 includes the following steps B1 to B2.

[0114] Step B1: Use light sources with wavelengths of 365nm, 530nm, 660nm, and 880nm to irradiate the sample to be tested, and record the photoelectric test data of the sample to be tested, which includes voltage, dark current, and photocurrent.

[0115] Step B2: Calculate standardized indicators of the sample to be tested based on the photoelectric test data, where the standardized indicators include at least one of photoelectric sensitivity, photoresponsivity, detectivity, and quantum efficiency.

[0116] In the disclosed embodiment, the standardized indicators may include photoelectric response parameters to standardize the photoelectric response performance of the two-dimensional GeSe film. Based on specific experimental conditions, test requirements and other factors, light sources with wavelengths of 365nm, 530nm, 660nm, and 880nm can be selected to perform irradiation tests on the test samples to obtain photoelectric test data, and the corresponding standardized indicators are calculated based on the photoelectric test data. Among them, the photoelectric test data may include voltage, dark current, photocurrent, etc. The photocurrent refers to the current excited by photon absorption under illumination conditions, and the dark current refers to the current induced under non-illumination conditions. The standardized indicators calculated based on the photoelectric test data may include photoelectric sensitivity, photoresponsivity, detection rate and quantum efficiency, etc.

[0117] For example, for the test samples corresponding to the glass slide, the test samples corresponding to the ceramic wafer, and the test samples corresponding to the oxide layer silicon wafer, light response parameters are measured using light sources with wavelengths of 365 nm, 530 nm, 660 nm, and 880 nm, respectively.

[0118] Figure 13 The two-dimensional GeSe thin film grown on the ceramic wafer in the embodiment of the present disclosure is shown in FIG. dark )、365nm(I 365nm )、530nm(I 530nm )、660nm(I 660nm )、880nm(I 880nm ) under the current (Current) - voltage (Voltage) curve, Figure 14 The current-time (T) curve of a two-dimensional GeSe thin film grown on a ceramic wafer under 100% power in an embodiment of the present disclosure is shown. Figure 15 The current-voltage curves of the two-dimensional GeSe thin film grown on a glass slide in the embodiment of the present disclosure at no light, 365nm, 530nm, 660nm, and 880nm are shown. Figure 16 : shows the current-time curve of a two-dimensional GeSe thin film grown on a glass slide in an embodiment of the present disclosure at 100% power, Figure 17 The current-voltage curves of the two-dimensional GeSe thin film grown on the oxide layer silicon wafer in the embodiment of the present disclosure are shown at no light, 365nm, 530nm, 660nm, and 880nm. Figure 18 The current-time curve of a two-dimensional GeSe film grown on an oxide-layer silicon wafer under 100% power in an embodiment of the present disclosure is shown.

[0119] As mentioned above Figures 13 to 18As shown, there is a good linear relationship between current (I) and voltage (V), indicating that the contact between the metal Ag electrode and the two-dimensional GeSe film is an ohmic contact. The photocurrent generated under illumination with light sources of different wavelengths is greater than its dark current, indicating that the photoelectric response can be generated under different light sources. Furthermore, the photocurrent response gradually increases with the increase in the wavelength of the light source. Under illumination with a wavelength of 880nm, the two-dimensional GeSe films grown on ceramic wafers, glass slides, and oxide-layer silicon wafers all exhibited the most significant photocurrent response.

[0120] Further, in-depth research was conducted based on 880nm light source irradiation. For the test samples corresponding to the glass slide, the test samples corresponding to the ceramic wafer, and the test samples corresponding to the oxide layer silicon wafer, the IV curve at 880nm and the current-time curve at 100% power can be referred to the above Figures 13 to 18 Furthermore, the disclosed embodiment also tested the change of current over time when 10% and 50% power were applied under 880nm illumination. Under the condition of 880nm wavelength light, the photocurrent increased with the increase of voltage, showing good photoelectric response characteristics.

[0121] Refer to the above Figure 13 、 15 As shown in Figure 17, the dark current, photocurrent and voltage show a linear relationship and exhibit good ohmic characteristics.

[0122] Refer to the above Figure 14 、 16 And 18. Under a bias voltage of 5V, the current-time response characteristics of two-dimensional GeSe films prepared on different substrates during the light switching cycle. The photocurrent shows obvious periodic changes, indicating that the response to the light signal is fast and repeatable.

[0123] Further analysis revealed that under a 5V bias voltage and 880nm wavelength illumination, the 2D GeSe thin film on a ceramic wafer had a photocurrent of 202nA, a dark current of 7.89nA, and a photoelectric sensitivity of 25.60. The 2D GeSe thin film on a glass slide had a photocurrent of 8581nA, a dark current of 2239nA, and a photoelectric sensitivity of 3.83. The 2D GeSe thin film on an oxide-layered silicon wafer had a photocurrent of 2387nA, a dark current of 84.4nA, and a photoelectric sensitivity of 28.28. The sensitivities of the 2D GeSe thin films fabricated on ceramic and oxide-layered silicon wafers were significantly higher than previously recorded, indicating superior photoelectric conversion efficiency.

[0124] Furthermore, it can be seen that the dark current of 2D GeSe films grown on ceramic and oxidized silicon wafers is lower than that of 2D GeSe films grown on glass slides. Analysis combined with SEM images reveals that the conductive paths of nanowires grown on ceramic and oxidized silicon wafers are much longer than those of nanoparticles grown on glass slides, thereby reducing dark current. Furthermore, the photosensitivity of 2D GeSe films grown on ceramic and oxidized silicon wafers is also greater than that of 2D GeSe films grown on glass slides. This indicates that the nanoparticle morphology has a smaller absorption area and exhibits significant lattice distortion and stress, which facilitates the capture of photogenerated carriers. In contrast, nanowires have a larger specific surface area, a larger absorption area, and less lattice distortion and stress between nanowires, allowing photogenerated carriers to be easily transferred between electrodes, resulting in relatively greater photoelectric sensitivity. Consequently, the photoelectric sensitivity of the oxidized silicon wafer is relatively the highest.

[0125] On this basis, standardized indicators such as photoelectric sensitivity (S), photoresponsivity (R), detectivity (D*) and quantum efficiency (E Q ), calculated using the following formulas (5), (6) and (7): (5) (6) (7) Among them, I p is the photocurrent, I d is the dark current, q=e=1.6×10 -19 C, C = 3 × 10 8 m / s,λ=880nm,P0=50mW / cm 2 , A=0.01cm 2 , h=6.625×10 -34 JS.

[0126] In an optional embodiment of the present disclosure, the optoelectronic test data further includes a response rise time and a recovery fall time.

[0127] In the embodiment of the present disclosure, the response rise time and recovery fall time of GeSe films grown on different substrates can be further tested. The response rise time can be the time required for the photocurrent to increase by a certain amplitude, and the recovery fall time can be the time required for the photocurrent to decrease by a certain amplitude. The specific amplitude can be set according to the test conditions and application requirements. The response rise time and recovery fall time can reflect the light response speed of the two-dimensional GeSe film. Different response rise times and recovery fall times can correspond to scenarios with different response requirements, such as high-speed optical communications and real-time imaging, which require relatively faster response speeds.

[0128] For example, the response rise time (τ r) is defined as the time required for the photocurrent to increase from 10% to 90%, and the recovery time (τ f ) is defined as the time required for the photocurrent to decrease from 90% to 10%. Based on this, the response rise time and recovery fall time of the test samples corresponding to the glass slide, the test samples corresponding to the ceramic wafer, and the test samples corresponding to the oxide layer silicon wafer were measured under 880nm light source.

[0129] Specifically, the GeSe film fabricated on a ceramic wafer exhibited a rise time of 16ms and a fall time of 55ms; the GeSe film fabricated on a glass slide exhibited a rise time of 34ms and a fall time of 128ms; and the GeSe film fabricated on an oxide-layered silicon wafer exhibited a rise time of 14ms and a fall time of 43ms. These rise and fall times significantly outperform existing photodetector records and can meet the needs of diverse application scenarios.

[0130] In summary, the photoelectric test data and photoelectric response parameters of different substrates are summarized in Table 6 below.

[0131] Table 6

[0132] As shown in Table 6 above, the calculated photoresponses of GeSe films grown on ceramic wafers, glass slides, and oxide-layer silicon wafers are 0.39 mA / W, 12.68 mA / W, and 4.61 mA / W, respectively; the quantum efficiencies are 0.06%, 1.79%, and 0.65%, respectively; and the detectivities are 7.76×10 8 , and 1.49×10 9 , and 2.80×10 9 The above standardized indicators show the differentiated effects of ceramic wafers, glass slides, and oxide-layer silicon wafers on the performance of two-dimensional GeSe thin films, thereby adapting to the application needs of different scenarios.

[0133] In an optional embodiment of the present disclosure, the standardized indicator includes a first-principles calculation result, and the aforementioned step 103 includes the following step C.

[0134] Step C: Calculate the two-dimensional GeSe thin film of each test sample based on the first principles to obtain standardized indicators; the standardized indicators include at least one of the top view of the two-dimensional GeSe structure, the side view of the two-dimensional GeSe structure, the partial wave state density, the band structure calculated based on the PBE functional, and the band structure calculated based on the HSE06 hybrid functional.

[0135] In the disclosed embodiments, while the standardized metrics include first-principles calculation results, systematic calculations can also be performed for each 2D GeSe thin film grown on the sample being tested. In this case, the standardized metrics can include top and side views of the constructed 2D GeSe thin film model, as well as its partial density of states (PDOS) and band structure. Based on this, different functionals can be used to calculate the band structure, such as the PBE functional and the HSE06 hybrid functional.

[0136] For example, Figure 19 1 shows a top view and a side view of a two-dimensional GeSe thin film model in an embodiment of the present disclosure, Figure 20 A schematic diagram of the partial-wave density of states of a two-dimensional GeSe film in an embodiment of the present disclosure is shown.

[0137] like Figure 19 As shown, the top view of the two-dimensional GeSe film model is shown. z Axis view) and side view ( x axis perspective).

[0138] like Figure 20 As shown in Figure 3, the peak of the p orbital near the Fermi level of the two-dimensional GeSe film is significantly higher than that of the s orbital, indicating that the p orbital plays a dominant role in the electronic structure.

[0139] Furthermore, calculations using the PBE functional and the HSE06 hybrid functional show that the band gap of the two-dimensional GeSe film is a direct band gap, with the conduction band bottom and valence band top located between Γ and F. In practical applications, electronic transitions in direct band gap materials do not require the participation of phonons, which facilitates their application in optoelectronic devices. Furthermore, a comparison of the overall trends calculated using the PBE functional and the HSE06 hybrid functional reveals that the band structure calculated using the PBE functional exhibits only a rigid translation compared to the HSE06 hybrid functional. Based on the calculation results of density functional theory, the band gap value of GeSe film under PBE functional is 1.168eV, which is close to the band gap of 1.185eV predicted by standard data and GeSe film grown on ceramic wafers in experiments, and the band gap of 1.031eV predicted by GeSe film grown on oxide silicon wafers; the GeSe band gap value calculated by HSE06 hybrid functional is 1.654eV, which is close to the band gap of 1.685eV predicted by standard data and GeSe film grown on glass slides in experiments.

[0140] In summary, based on the first-principles calculation results, it can be shown that the two-dimensional GeSe film has good electronic structure characteristics and can meet the application requirements in the field of optoelectronic devices.

[0141] The performance testing method of the two-dimensional GeSe film provided by the present disclosure uses physical vapor deposition to prepare two-dimensional GeSe films on different types of substrates, and prepares electrodes on the two-dimensional GeSe films to construct test samples; pre-constructed standardized indicators are tested on each test sample, and on this basis, the performance test results corresponding to different types of substrates are determined; wherein, the standardized indicators may include composition and structure characterization, photoelectric response parameters, and first-principles calculation results. This scheme can obtain performance test results based on standardized indicators for two-dimensional GeSe films prepared by physical vapor deposition on different types of substrates. Through standardized indicators, the mechanism of the influence of multiple types of substrates on the performance of two-dimensional GeSe films can be comprehensively and accurately explored, which can fully explore the characteristics of two-dimensional GeSe films, thereby accurately and efficiently guiding the selection of substrates in the preparation process of two-dimensional GeSe films under different application requirements.

[0142] Figure 21 A flow chart showing the steps of the method for preparing a two-dimensional GeSe thin film according to an embodiment of the present disclosure is shown. Figure 21 As shown, the method may include the following steps 2101 to 2103.

[0143] Step 2101: Obtain application performance requirements of the two-dimensional GeSe thin film.

[0144] In the embodiments of the present disclosure, when preparing a two-dimensional GeSe film, application performance requirements can be determined, such as process cost requirements, film morphology requirements, and optical performance requirements. Optical performance requirements can include photocurrent intensity, response rise time, response time degradation, etc. Those skilled in the art can evaluate and determine the application performance requirements of the two-dimensional GeSe film based on actual conditions.

[0145] Step 2102: Match the performance test results corresponding to different types of substrates based on application performance requirements. The performance test results are obtained by the aforementioned two-dimensional GeSe thin film performance test method.

[0146] In the disclosed embodiments, based on the application performance requirements, performance test results corresponding to different types of substrates can be matched. The performance test requirements are obtained by using the aforementioned two-dimensional GeSe thin film performance test method to test two-dimensional GeSe thin films prepared on different types of substrates based on pre-established standardized indicators.

[0147] For example, after preparing two-dimensional GeSe thin films on ceramic wafers, glass slides and oxide-layer silicon wafers by physical vapor deposition, standardized indicators such as composition and structure characterization, photoelectric response parameters, and first-principles calculation results were tested, and their performance test results were obtained. Among them, XRD, SEM and other results show that among the ceramic wafers, glass slides and oxide-layer silicon wafers, the GeSe nanowires prepared on the oxide-layer silicon wafer have the highest crystal quality and good diameter uniformity, the relative intensity of the (111) diffraction peak is the highest, and the stress is relatively minimal. On this basis, it is also shown that the GeSe film tends to grow along the (111) crystal direction and has a small compressive stress or lattice distortion, which can reflect that the lattice mismatch between the GeSe film and the oxide-layer silicon wafer is small. In the analysis of photoelectric response parameters, under the irradiation of a light source with a wavelength of 880nm, the GeSe films prepared on the ceramic wafers, glass slides and oxide-layer silicon wafers show different sensitivities, response rise times and recovery fall times.

[0148] Application performance requirements can be matched against the above differentiated performance test results to determine the substrate type selection that may meet the requirements.

[0149] Step 2103: Using physical vapor deposition, prepare a two-dimensional GeSe thin film on a substrate whose performance test results match the application performance requirements.

[0150] In the disclosed embodiments, when performance test results match application performance requirements, a substrate type corresponding to the performance test results can be selected. For example, when the application performance requirements match those corresponding to a glass slide, physical vapor deposition (PVD) can be used to fabricate a two-dimensional GeSe thin film on a glass slide substrate. The same applies to ceramic wafers and oxide-layer silicon wafers.

[0151] On this basis, when the performance test results are similar to the application performance requirements, a substrate with similar materials and properties can be selected based on the substrate type corresponding to the performance test results to prepare a two-dimensional GeSe thin film. The embodiments of the present disclosure do not impose specific restrictions on this.

[0152] The disclosed method for preparing a two-dimensional GeSe thin film can determine application performance requirements when preparing the two-dimensional GeSe thin film, match the application performance requirements with performance test results corresponding to different types of substrates, and use physical vapor deposition to prepare the two-dimensional GeSe thin film on a substrate whose performance test results match the application performance requirements; wherein the performance test results are based on the aforementioned performance test method for two-dimensional GeSe thin films. This solution can combine actual application performance requirements with performance test results to match and select appropriate substrates when preparing two-dimensional GeSe thin films, thereby enabling flexible and targeted preparation of two-dimensional GeSe thin films that meet application requirements in different environments, further fully and deeply exploring the application potential of two-dimensional GeSe.

[0153] It should be noted that although the steps of the method of the present disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in this specific order, or that all steps must be performed to achieve the desired results. Additional or alternative steps, such as omitting certain steps, combining multiple steps into one step, and / or decomposing a step into multiple steps, should all be considered part of this disclosure.

[0154] It should be understood that the present disclosure is not limited in its application to the detailed structure and arrangement of the components proposed in this specification. The present disclosure is capable of other embodiments and can be implemented and executed in a variety of ways. The aforementioned variations and modifications fall within the scope of the present disclosure. It should be understood that the present disclosure disclosed and defined in this specification extends to all alternative combinations of two or more individual features mentioned or evident in the text and / or the drawings. All of these different combinations constitute multiple alternative aspects of the present disclosure. The embodiments of this specification illustrate the best mode known for implementing the present disclosure and will enable those skilled in the art to utilize the present disclosure.

Claims

1. A performance testing method for a two-dimensional GeSe thin film, characterized in that: The method comprises: Select at least two different types of substrates; A two-dimensional GeSe film is prepared on each substrate by physical vapor deposition, and an electrode is prepared on the two-dimensional GeSe film to obtain test samples corresponding to different types of substrates; Testing a pre-established standardized index on each of the test samples; the standardized index includes at least one of composition and structure characterization, photoelectric response parameters, and first-principles calculation results; Based on the standardized indicators of the samples to be tested, performance test results corresponding to different types of substrates are determined respectively.

2. The performance testing method of the two-dimensional GeSe thin film according to claim 1, characterized in that: The types of the substrate include transparent substrate and non-transparent substrate; The transparent substrate comprises a glass slide; The non-transparent substrate includes a ceramic wafer and an oxide layer silicon wafer.

3. The performance testing method of the two-dimensional GeSe thin film according to claim 1, characterized in that: The standardized indicators include composition and structural characterization, and the pre-constructed standardized indicators are tested on each of the samples to be tested, including: Characterizing each of the test samples using an X-ray diffraction pattern to obtain at least one of the phase composition, crystal structure, grain size, and crystal strain of the test sample; and / or, characterizing each of the test samples using Raman spectroscopy, and analyzing the material composition of the test samples based on molecular vibration modes; and / or, characterizing each of the samples to be tested using a scanning electron microscope image to obtain at least one of the surface morphology and microstructure of the sample to be tested; and / or, characterizing each of the samples to be tested using scanning electron microscope images combined with energy dispersive X-ray spectroscopy to obtain at least one of the elemental composition and elemental distribution of the sample to be tested; And / or, each of the samples to be tested is characterized respectively by using X-ray photoelectron spectroscopy to obtain the GeSe fitting binding energy of the sample to be tested.

4. The performance testing method of the two-dimensional GeSe thin film according to claim 2, characterized in that: The standardized indicators include composition and structural characterization, the substrate is a transparent substrate, and the pre-established standardized indicators are tested on each of the samples to be tested, including: Characterizing each of the test samples using ultraviolet-visible-near infrared spectroscopy to obtain optical properties and band gap values of the test samples; Alternatively, the standardized indicators include composition and structural characterization, the substrate is a non-transparent substrate, and the pre-established standardized indicators are tested on each of the samples to be tested, including: Each of the samples to be tested is characterized by using diffuse reflectance spectroscopy to obtain the optical properties and band gap value of the sample to be tested.

5. The performance testing method of the two-dimensional GeSe thin film according to claim 1, characterized in that: The standardized index includes a photoelectric response parameter, and the pre-constructed standardized index is tested on each of the test samples, including: Irradiating the sample to be tested with light sources having wavelengths of 365 nm, 530 nm, 660 nm, and 880 nm, respectively, and recording photoelectric test data of the sample to be tested, wherein the photoelectric test data includes voltage, dark current, and photocurrent; A standardized index of the sample to be tested is calculated based on the photoelectric test data, where the standardized index includes at least one of photoelectric sensitivity, photoresponsivity, detectivity, and quantum efficiency.

6. The performance testing method of the two-dimensional GeSe thin film according to claim 5, characterized in that: The optoelectronic test data also includes response rise time and recovery fall time.

7. The performance testing method of the two-dimensional GeSe thin film according to claim 1, characterized in that: The standardized indicators include first principles calculation results, and the pre-constructed standardized indicators are tested on each of the samples to be tested, including: Based on the first principles, the two-dimensional GeSe thin film of each test sample is calculated to obtain the standardized indicators; the standardized indicators include at least one of the top view of the two-dimensional GeSe structure, the side view of the two-dimensional GeSe structure, the partial wave state density, the band structure calculated based on the PBE functional, and the band structure calculated based on the HSE06 hybrid functional.

8. A method for preparing a two-dimensional GeSe thin film, characterized in that: The method comprises: Obtain application performance requirements for two-dimensional GeSe thin films; Matching the performance test results corresponding to different types of substrates based on the application performance requirements, the performance test results being obtained by testing the two-dimensional GeSe thin film performance testing method according to any one of claims 1 to 7; The two-dimensional GeSe thin film is prepared on a substrate whose performance test results match the application performance requirements by using a physical vapor deposition method.

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