Method for continuously adjusting Fermi level position of nitride surface

Abstract

The invention provides a method for continuously adjusting the Fermi level position of a nitride surface, which comprises the following steps: depositing on the nitride surface through a physical deposition or chemical deposition process to obtain a load layer, and forming the load layer on the nitride surface by controlling deposition reaction process parameters; and controlling the thickness of the load layer according to the relationship between the deposition reaction process parameters and the thickness of the load layer so as to continuously adjust the Fermi level position of the nitride surface. On the other hand, the invention discloses application of the nitride obtained according to the method, the application comprises photoelectrocatalysis, photocatalysis and semiconductor surface heterogeneous integration, and the surface Fermi level position of the nitride can be continuously adjusted.

Description

Technical Field

[0001] The present disclosure belongs to the field of semiconductor materials, and in particular relates to a method for continuously adjusting the Fermi level position on the surface of a nitride. Background Art

[0002] Nitride semiconductor is a new type of semiconductor material, the main components of which are gallium nitride, aluminum nitride and indium nitride. It is a highly regarded material in the preparation of traditional semiconductor devices, new energy conversion and photoelectric catalysis. They have attracted widespread attention due to their high specific surface area, superior electron transport performance and large-scale production. However, the inherent fragility of the nitride surface, such as susceptibility to damage and sensitivity to manufacturing technology, poses a major challenge to controlling its surface properties, which has become a key limiting factor hindering the development of gallium nitride-based devices. Specifically, the position of the Fermi level on the nitride surface determines the use function of the nitride and greatly affects the device performance of the nitride. In related technologies, how to control the surface Fermi level position of nitride has been widely studied, and the main design strategies are divided into surface modification during the material growth synthesis stage and after the material synthesis.

[0003] During the material growth and synthesis stage, the surface Fermi level of the nitride is usually designed according to the target performance during the material growth process and adjusted to a fixed value. Then the p-type or n-type doping concentration of the nitride is regulated. The surface energy band bending of the nitride nanowires is controlled by changing the doping concentration. However, this method can often only be used during the material growth stage and has great limitations. It also requires complex material growth equipment, and the growth process is complicated and has high economic costs, making it unsuitable for large-scale use.

[0004] However, in the post-synthesis stage of materials, only a single energy band regulation can be performed, and it is impossible to achieve continuity. For example, in the post-synthesis stage of materials, the surface modification or surface passivation of nitride nanowires is the main method. Surface passivation usually uses acids, alkalis, and organic substances to treat its surface to remove its surface state, making it difficult to control its Fermi level change. Surface modification usually involves constructing a heterojunction on its surface. Since the modified substance has a fixed work function, it can only cause the Fermi level on the surface of the nitride nanowire to move to a fixed position. If you want to achieve Fermi level regulation at different positions, you can only further screen materials with matching work functions to form new heterojunctions with nitride nanowires. The experiment is complicated, and the time and economic costs are too high. It lacks the ability to accurately control the surface properties of nitrides, and is not easy to use on a large scale.

[0005] Therefore, finding a method to continuously adjust the Fermi level of the nitride surface has far-reaching significance for supplementing or simplifying the design and shortening the time in practical applications. Summary of the invention

[0006] In view of this, in order to solve at least one technical problem in the related art and other aspects, the present disclosure proposes a method for continuously adjusting the Fermi level position on the surface of a nitride, comprising:

[0007] Depositing a load layer on the surface of the nitride by a physical deposition or chemical deposition process, and forming a load layer on the surface of the nitride by controlling deposition reaction process parameters;

[0008] According to the relationship between the deposition reaction process parameters and the support layer thickness, the support layer thickness is controlled to continuously adjust the Fermi level position on the nitride surface.

[0009] According to an embodiment of the present disclosure, the material of the support layer includes a carbon layer and a disulfide layer.

[0010] According to an embodiment of the present disclosure, the physical deposition process includes one of magnetron sputtering, plasma sputtering, atomic layer deposition technology, pulsed laser beam deposition, and molecular beam epitaxy.

[0011] According to an embodiment of the present disclosure, the chemical deposition process includes one of metal organic chemical vapor deposition growth, immersion calcination method, and cyclic voltammetry.

[0012] According to an embodiment of the present disclosure, the reaction process parameters include reaction time, reactant concentration, reaction temperature, reaction flow rate and reaction vacuum degree.

[0013] According to an embodiment of the present disclosure, the thickness of the support layer is from a single atomic layer thickness to 10 um.

[0014] According to an embodiment of the present disclosure, the semiconductor structure type of nitride includes intrinsic nitride, pn homojunction or heterojunction formed by n-type doping or p-type doping of nitride, np homojunction or heterojunction, pin homojunction or heterojunction, and one of the structures including a tunneling junction.

[0015] According to an embodiment of the present disclosure, the nitride includes GaN, Al x Ga 1-x N、In x Ga 1-x N、In y Al x Ga 1-x-y N.B x Al y Ga 1-x-y N.B x In y Ga 1-x-y At least one of N; wherein, 0≤x≤1, 0≤y≤1, x+y≤1.

[0016] According to an embodiment of the present disclosure, the shape of the nitride includes one of a nanowire, a nanocolumn, a planar structure, a triangular pyramid, and an irregular structure; wherein the shape of the nanocolumn is a polygon or an irregular shape.

[0017] In another aspect of the present disclosure, an application of the nitride obtained according to the above method is disclosed, the application includes photoelectrocatalysis, photocatalysis and semiconductor surface heterogeneous integration, wherein the surface Fermi level position of the nitride can be continuously adjusted.

[0018] According to the embodiments of the present disclosure, by establishing a load layer on the nitride surface, the difference in electron transfer between the load layer of different thickness and the nitride leads to a continuous change in the Fermi level of the nitride surface. At the same time, in the present disclosure, a simple material surface modification strategy is used, that is, by controlling the relationship between the deposition reaction process parameters corresponding to the load layer and the thickness of the load layer, to achieve continuous regulation of the surface Fermi level position of the nitride material. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a transmission electron micrograph of the nitride after loading in Example 1 of the present disclosure;

[0020] Figure 2 is a transmission electron micrograph of the nitride after loading in Example 2 of the present disclosure;

[0021] Figure 3 is a transmission electron micrograph of the nitride after loading in Example 3 of the present disclosure;

[0022] Figure 4 is a transmission electron micrograph of the nitride after loading in Example 4 of the present disclosure;

[0023] Figure 5 is a line graph of the relative distribution of the Fermi level position on the surface of the nitride after loading in Examples 1 to 4 of the present disclosure;

[0024] Figure 6 It is the XPS elemental analysis characterization diagram of the surface of the nitride after loading in Examples 1 to 4 of the present disclosure, wherein Figure a is the C1s spectrum and Figure b is the N1s spectrum;

[0025] Figure 7 is a transmission electron micrograph of the nitride after loading in Example 5 of the present disclosure;

[0026] Figure 8 is a transmission electron micrograph of the nitride after loading in Example 6 of the present disclosure;

[0027] Fig. 9 is a transmission electron micrograph of the nitride after loading in Example 7 of the present disclosure;

[0028] Fig.10 is a transmission electron micrograph of the nitride after loading in Example 8 of the present disclosure;

[0029] Fig.11 is a line graph of the average contact potential difference distribution of the nitride surface after loading in Examples 5 to 8 of the present disclosure;

[0030] Fig.12 This is a photocatalytic performance test diagram in the application example of the present disclosure. DETAILED DESCRIPTION

[0031] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0032] The endpoints and any values ​​of the ranges disclosed in this disclosure are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in this disclosure.

[0033] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0034] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

[0035] Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or configurations will be omitted when they may cause confusion in the understanding of the present disclosure. The shapes, sizes, and positional relationships of the components in the drawings do not reflect the actual size, proportion, and actual positional relationship. In addition, in the present disclosure, any reference symbol between brackets should not be constructed as a limitation to the present disclosure.

[0036] Similarly, in order to simplify the present disclosure and help understand one or more of the various disclosed aspects, in the above description of the exemplary embodiments of the present disclosure, the various features of the present disclosure are sometimes grouped together into a single embodiment, figure, or description thereof. The description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0037] In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0038] In the present disclosure, the essence of the change in the position of the Fermi level on the nitride surface is to construct a heterojunction structure by forming a load layer on the nitride surface, and there is charge transfer between the load layer and the nitride surface, which in turn affects the position of the Fermi level on the nitride surface. Therefore, the difference in the position of the Fermi level on the surface and inside the nitride will cause the generation of a built-in electric field, thereby causing a change in the curvature of the nitride surface energy band. The applicant has found that the degree of electron transfer between load layers of different thicknesses and nitrides is different, and the surface Fermi level position of gallium nitride nanowires can be continuously regulated according to the thickness of the deposited load layer, thereby continuously regulating its energy band curvature to make it more suitable for practical applications.

[0039] The present disclosure proposes a method for continuously adjusting the Fermi level position of a nitride surface, comprising:

[0040] The load layer is deposited on the nitride surface by physical deposition or chemical deposition process, and the load layer is formed on the nitride surface by controlling the deposition reaction process parameters. According to the relationship between the deposition reaction process parameters and the load layer thickness, the load layer thickness is controlled to continuously adjust the Fermi level position on the nitride surface.

[0041] According to the embodiments of the present disclosure, by establishing a load layer on the nitride surface, the difference in electron transfer between the load layer of different thickness and the nitride leads to a continuous change in the Fermi level of the nitride surface. At the same time, in the present disclosure, a simple material surface modification strategy is used, that is, by controlling the relationship between the deposition reaction parameters corresponding to the load layer and the thickness of the load layer, to achieve continuous regulation of the surface Fermi level position of the nitride material.

[0042] According to an embodiment of the present disclosure, the material of the support layer includes a carbon layer and a disulfide layer.

[0043] In some specific embodiments, the reactant solution of the deposition reaction includes one of a polycarbon compound solution and an ammonium tetrathiomolybdate solution, and the concentration of the reactant solution is 0.01 to 20 mg / ml. For example, the concentration of the reactant solution may be 0.01 to 20 mol / L, for example, 0.05 mol / L, 1 mol / L, 2 mol / L, 3 mol / L, 4 mol / L, 5 mol / L, 10 mol / L, 15 mol / L, 20 mol / L, etc.

[0044] According to an embodiment of the present disclosure, the change in the thickness of the load layer can be achieved by controlling the concentration of the deposition reactant solution. Within a certain range, the higher the concentration of the reactant solution, the thicker the load layer, and the greater the change in the Fermi level position on the nitride surface.

[0045] According to an embodiment of the present disclosure, the physical deposition process includes one of magnetron sputtering, plasma sputtering, atomic layer deposition technology, pulsed laser beam deposition, and molecular beam epitaxy.

[0046] According to an embodiment of the present disclosure, the chemical deposition process includes one of metal organic chemical vapor deposition growth, immersion calcination method, and cyclic voltammetry.

[0047] According to an embodiment of the present disclosure, the reaction process parameters include reaction time, reactant concentration, reaction temperature, reaction flow rate and reaction vacuum degree.

[0048] According to an embodiment of the present disclosure, the thickness of the support layer is from a single atomic layer thickness to 10 um.

[0049] In some specific embodiments, the operation of the impregnation calcination method includes: soaking the nitride in a polycarbon compound solution for 1 to 48 hours and then taking it out, calcining the soaked nitride at 100 to 650° C. for 0.5 to 4 hours in an inert gas atmosphere to form a load layer on the surface of the nitride.

[0050] In some specific embodiments, the immersion time of the nitride in the polycarbon compound solution can be 1h, 12h, 24h, 36h, 48h, etc., the calcination temperature can be 100°C, 200°C, 300°C, 400°C, 500°C, 650°C, etc., and the calcination time can be 0.5h, 1h, 2h, 3h, 4h, etc.

[0051] In some specific embodiments, the multi-carbon compound solution includes at least one of a glucose aqueous solution, a sucrose aqueous solution, and a xylitol aqueous solution.

[0052] In some specific embodiments, when the reactant solution is a multi-carbon compound solution, the deposition reaction process parameter for controlling the thickness of the support layer is the concentration of the reactant solution.

[0053] According to the embodiments of the present disclosure, when the reactant solution is a multi-carbon compound solution, the position of the Fermi level on the nitride surface can be effectively and continuously adjusted according to the corresponding relationship by adjusting the concentration of the reactant solution.

[0054] In some specific embodiments, the operation of cyclic voltammetry includes: placing the nitride in an ammonium tetrathiomolybdate solution, and performing electrodeposition using cyclic voltammetry in a three-electrode system at a voltage range of -0.1 to -0.8 V relative to the standard hydrogen potential, with the number of deposition cycles being 5 to 50 cycles, to form a load layer on the surface of the nitride.

[0055] According to the embodiments of the present disclosure, the change in the thickness of the load layer can be achieved by controlling its electrodeposition process parameters. Within a certain range, the more electrodeposition cycles there are and the thicker the load layer is, the greater the change in the Fermi level position on the nitride surface.

[0056] In some specific embodiments, when the reactant solution is an ammonium tetrathiomolybdate solution, the deposition reaction process parameters for controlling the thickness of the support layer are the number of electrodeposition voltammetric cycles and the concentration of the reactant solution.

[0057] According to an embodiment of the present disclosure, when the reactant solution is an ammonium tetrathiomolybdate solution, the position of the Fermi level on the nitride surface can be effectively and continuously adjusted according to the corresponding relationship by adjusting the number of cyclic voltammetry cycles in the electrodeposition operation.

[0058] According to an embodiment of the present disclosure, the supporting layer in the technical solution of the present disclosure may also be a metal organic framework MOF layer, a covalent organic framework COF layer, etc.

[0059] According to an embodiment of the present disclosure, the semiconductor structure type of nitride includes intrinsic nitride, pn homojunction or heterojunction formed by n-type doping or p-type doping of nitride, np homojunction or heterojunction, pin homojunction or heterojunction, and one of the structures including a tunneling junction.

[0060] According to an embodiment of the present disclosure, the nitride includes GaN, Al x Ga 1-x N、In x Ga 1-x N、In y Al x Ga 1-x-y N.B x Al y Ga 1-x-y N.B x Iny Ga 1-x-y At least one of N; wherein, 0≤x≤1, 0≤y≤1, x+y≤1.

[0061] According to an embodiment of the present disclosure, the shape of the nitride includes one of a nanowire, a nanocolumn, a planar structure, a triangular pyramid, and an irregular structure; wherein the shape of the nanocolumn is a polygon or an irregular shape.

[0062] In another aspect of the present disclosure, an application of the nitride obtained according to the above method is disclosed, the application includes photoelectrocatalysis, photocatalysis and semiconductor heterogeneous integration, wherein the surface Fermi level position of the nitride can be continuously adjusted.

[0063] According to an embodiment of the present disclosure, the application of the nitride obtained according to the above method specifically includes photoelectrocatalysis or photocatalytic water decomposition, carbon dioxide reduction, nitrogen reduction, organic matter decomposition and heteroepitaxial growth.

[0064] According to the embodiments of the present disclosure, the method of continuously adjusting the Fermi level position of the nitride surface proposed in the present disclosure can be applied to various fields, such as energy conversion fields such as photoelectrocatalysis and photocatalysis, or semiconductor integrated epitaxy, to provide better device performance and construct more new device structures.

[0065] According to the embodiments of the present disclosure, continuously regulating the Fermi level of the nitride surface can, on the one hand, increase the application scenarios of nitrides in catalytic reactions, and can continuously regulate the degree of band bending on the nitride surface by changing the Fermi level, so that it can reasonably design the degree of band bending that is most suitable for a specific catalytic scenario, so that the utilization rate of photogenerated carriers in the nitride catalytic reaction is the highest, and the optimal catalytic performance is achieved; on the other hand, it is conducive to heterogeneous integration between semiconductors. By controlling the Fermi level position on the surface and changing the contact potential difference with other materials, it can form a Schottky contact or an Ohmic contact with a metal electrode, greatly increasing the selectivity of the device function. At the same time, the continuously adjustable Fermi level enables it to be integrated with a variety of other heterogeneous materials with different Fermi levels for design, achieving band alignment with different materials, which is conducive to the development of multifunctional devices.

[0066] It should be noted that the described embodiments are only part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments of the present disclosure, other embodiments obtained by ordinary technicians in the field without creative work are all within the scope of protection of the present disclosure.

[0067] Example 1

[0068] A loading layer with different thicknesses is loaded on the surface of p-type GaN.

[0069] 1. Prepare the reactant solution

[0070] Deionized water is used as solvent to prepare a 1 mol / L glucose aqueous solution, and the reactants also include sucrose, xylitol and other multi-carbon compounds.

[0071] 2. Impregnation

[0072] Place gallium nitride into the aqueous solution of the reactant, soak for 18 hours, take it out, and gently blow dry the surface with an ear bulb.

[0073] 3. Calcination

[0074] In a nitrogen atmosphere, the sample was calcined at 550°C for 3 hours, taken out, washed with ethanol and deionized water in turn, and dried to form a loading layer on the surface of gallium nitride, causing the position of the Fermi level on the surface of gallium nitride to change, which was recorded as C-2.

[0075] Example 2

[0076] This is a control experiment with Example 1, wherein, different from Example 1, in Example 2, the glucose concentration is 2 mol / L, which is recorded as C-3.

[0077] Example 3

[0078] This is a control experiment with Example 1, wherein, different from Example 1, in Example 3, the glucose concentration is 3 mol / L, denoted as C-4.

[0079] Example 4

[0080] This is a control experiment with Example 1, wherein, different from Example 1, in Example 4, the glucose concentration is 4 mol / L, which is recorded as C-5.

[0081] Test Example 1

[0082] The morphology of the loaded gallium nitride in Examples 1-4 was observed using a transmission electron microscope.

[0083] Figure 1-Figure 4 They are transmission electron micrographs of the loaded nitrides in Examples 1-4 of the present disclosure respectively.

[0084] Depend on Figure 1-Figure 4 It can be seen that the supported layer of C-2 is 3.85 nm, the supported layer of C-3 is 5.25 nm, the supported layer of C-4 is 8.35 nm, and the supported layer of C-5 is 10.05 nm.

[0085] In the present disclosure, the applicant has obtained the relationship between the reaction parameters of the deposition reaction and the thickness of the load layer through a large number of experimental simulations: h=2.1m-0.85, where h is the thickness of the load layer and m is the concentration of the reactant solution.

[0086] Test Example 2

[0087] Ultraviolet photoelectron spectroscopy (UPS) was used to observe the binding energy information of the GaN loaded in Examples 1-4, where C-2 represents the lowest loading layer thickness, and the loading layer thicknesses of C-3, C-4, and C-5 increase in sequence. F represents the Fermi level position, E V The E in the UV photoelectron spectroscopy UPS is F -E V It reflects the distance from the top of the valence band on the GaN surface to the Fermi level. Therefore, the change in this distance also reflects the change in the Fermi level on the GaN surface, which leads to the change in the curvature of the surface energy band.

[0088] Figure 5 It is a line graph of the relative distribution of the Fermi level position on the surface of the nitride after loading in Examples 1 to 4 of the present disclosure.

[0089] like Figure 5 As shown in the figure, with the increase of the thickness of the load layer, the surface Fermi level of p-type GaN changes continuously, and the surface band bending of gallium nitride also changes continuously. Compared with the pure sample, the surface Fermi level position changes more, and the surface band bending degree gradually decreases. In the present disclosure, the applicant has obtained the relationship between the surface Fermi level position of nitride and the thickness of the load layer through a large number of experimental simulations: n = 0.02h 2 -0.29h+4.01, where n is the Fermi level position of the nitride surface and h is the thickness of the loading layer.

[0090] Test Example 3

[0091] X-ray photoelectron spectroscopy (XPS) was used to observe the orbital excitation energy information of the unloaded p-type gallium nitride material and the loaded gallium nitride in Examples 1-4.

[0092] Figure 6 It is the XPS elemental analysis characterization diagram of the nitride surface after loading in Examples 1 to 4 of the present disclosure, wherein Figure a is the C1s spectrum and Figure b is the N1s spectrum.

[0093] like Figure 6As shown, the binding energy of the C 1s spectrum moves toward low energy as the thickness of the loading layer increases. At the same time, the binding energy of the N1s spectrum moves toward high energy as the thickness of the loading layer increases, indicating that as the thickness of the loading layer increases, the electron transfer between it and gallium nitride increases. In addition, in the C1s spectrum and the N1s spectrum, after the loading layer is realized, peaks representing the CN bond appear, and as the thickness of the loading layer increases, the peak intensity representing the bond becomes stronger and stronger, and its content ratio increases, indicating that as the thickness increases, the interaction between the loaded carbon layer and gallium nitride becomes stronger and stronger, which further explains that the position of the Fermi level on the nitride surface can be continuously and effectively adjusted by controlling the thickness of the loading layer.

[0094] Example 5

[0095] 1. Prepare ammonium tetrathiomolybdate [(NH 4 ) 2 MoS 4 ] aqueous solution as the reactant solution.

[0096] 2. Place n-type gallium nitride into the aqueous solution of the reactant and use a three-electrode system for electrodeposition, with a Pt mesh as the counter electrode and silver / silver chloride as the reference electrode. Cyclic voltammetry is used for deposition in a voltage range of -0.1-0.8 V relative to the standard hydrogen potential. The number of cyclic voltammetry cycles is 3, and a molybdenum disulfide loading layer is formed on the surface of gallium nitride, causing the position of the Fermi level on the surface of gallium nitride to change, which is recorded as Mo-1.

[0097] The thickness of GaN with different disulfide loading can be controlled by adjusting the deposition cycle number of cyclic voltammetry or the concentration of reactant solution.

[0098] Example 6

[0099] This is a control experiment with Example 5, wherein, different from Example 5, in Example 6, the number of cyclic voltammetry cycles is 6, which is recorded as Mo-2.

[0100] Example 7

[0101] This is a control experiment with Example 5, wherein, different from Example 5, in Example 6, the number of cyclic voltammetry cycles is 9, and is recorded as Mo-3.

[0102] Example 8

[0103] This is a control experiment with Example 5, wherein, different from Example 5, in Example 6, the number of cyclic voltammetry cycles is 12, and is recorded as Mo-4.

[0104] Test Example 4

[0105] The morphology of the loaded gallium nitride in Examples 5-8 was observed using a transmission electron microscope.

[0106] Figure 7-10 This is a transmission electron micrograph of the loaded nitride in Example 5 of the present disclosure.

[0107] Depend on Figure 7-10 It can be seen that the molybdenum disulfide loading layer of Mo-1 is 1.35 nm, the molybdenum disulfide loading layer of Mo-2 is 2.25 nm, the molybdenum disulfide loading layer of Mo-3 is 3.18 nm, and the molybdenum disulfide loading layer of Mo-4 is 4.23 nm.

[0108] In the present disclosure, the applicant has obtained the relationship between the number of cyclic voltammetry cycles and the thickness of the load layer through a large number of experimental simulations: h=0.319p+0.385, where p is the number of cyclic voltammetry cycles and h is the thickness of the load layer.

[0109] Test Example 5

[0110] The surface potential distribution (KPFM) of the GaN loaded in Examples 5-8 was observed using a Kelvin probe microscope. In this test example, Pt was used as a probe. The surface Fermi level Φ GaN =CPD GaN +Φ tip , where Φ tip =5.6eV, which is the work function of Pt.

[0111] Fig.11 It is a line graph of the average contact potential difference distribution on the nitride surface after loading in Examples 5 to 8 of the present disclosure.

[0112] like Fig.11 As shown in the figure, with the increase of the molybdenum disulfide loading layer, the average contact potential difference changes continuously, and the surface Fermi level of n-type gallium nitride changes continuously, specifically, the surface Fermi level of Mo-1 is 5.47eV, the surface Fermi level of Mo-2 is 5.56eV, the surface Fermi level of Mo-3 is 5.61eV, and the surface Fermi level of Mo-4 is 5.65eV. Since the position of the internal Fermi level of gallium nitride remains unchanged, the curvature of the surface energy band of n-type gallium nitride changes continuously with the change of the surface Fermi level.

[0113] In the present disclosure, the applicant has obtained the relationship between the Fermi level position on the nitride surface and the thickness of the load layer through a large number of experimental simulations: n = -0.16h 2 +0.158h+5.28, where h is the thickness of the loading layer and n is the Fermi level position of the nitride surface.

[0114] Application Examples

[0115] All samples in Examples 1 to 4 were subjected to photocatalytic water splitting experiments, and it was found that sample C-5 had the best photocatalytic water splitting performance, such as Fig.12 This is because the load layer adjusts the position of the Fermi level on the surface of the GaN nanowire, thereby adjusting the curvature of the surface energy band of the nanowire, which is more conducive to the photogenerated electrons and holes entering the solution to react, thereby improving the photolysis water performance.

[0116] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above description is only a specific embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A method for continuously adjusting the Fermi level position on a nitride surface, comprising: Depositing a load layer on the surface of the nitride by a physical deposition or chemical deposition process, and forming the load layer on the surface of the nitride by controlling the deposition reaction process parameters; According to the relationship between the deposition reaction process parameters and the support layer thickness, the support layer thickness is controlled to continuously adjust the Fermi level position on the nitride surface.

2. The method according to claim 1, wherein: The material of the supporting layer includes a carbon layer and a disulfide layer.

3. The method according to claim 1, wherein: The physical deposition process includes one of magnetron sputtering, plasma sputtering, atomic layer deposition technology, pulsed laser beam deposition, and molecular beam epitaxy.

4. The method according to claim 1, wherein: The chemical deposition process includes one of metal organic chemical vapor deposition growth, immersion calcination method and cyclic voltammetry.

5. The method according to claim 1, wherein: The reaction process parameters include reaction time, reactant concentration, reaction temperature, reaction flow rate and reaction vacuum degree.

6. The method according to claim 1, wherein: The thickness of the support layer is from a single atomic layer to 10 um.

7. The method according to claim 1, wherein: The semiconductor structure type of the nitride includes intrinsic nitride, pn homogeneous or heterogeneous junction formed by n-type doping or p-type doping of nitride, np homogeneous or heterogeneous junction, pin homogeneous or heterogeneous junction and one of the structures including tunnel junction.

8. The method according to claim 1, wherein: The nitride includes GaN, Al x Ga 1-x N、In x Ga 1-x N、In y Al x Ga 1-x-y N.B x Al y Ga 1-x-y N.B x In y Ga 1-x-y At least one of N; wherein, 0≤x≤1, 0≤y≤1, x+y≤1.

9. The method according to claim 8, wherein: The shape of the nitride includes one of a nanowire, a nanocolumn, a planar structure, a triangular pyramid, and an irregular structure; wherein the shape of the nanocolumn is a polygon or an irregular shape.

10. An application of the nitride obtained by the method according to any one of claims 1 to 9, the application comprising photoelectrocatalysis, photocatalysis and semiconductor heterogeneous integration; wherein, The surface Fermi level position of the nitride can be continuously adjusted.

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