A p-type gallium oxide material and its preparation method and application

Abstract

The present invention relates to the technical field of crystal materials, and specifically discloses a p-type gallium oxide material and a preparation method and application thereof. The present invention successfully realizes the preparation of p-type gallium oxide material by constructing a divalent metal-doped gallium oxide nanocolumn structure in a gallium oxide epitaxial layer to reduce the hole activation energy and increase the hole concentration. The present invention effectively solves the problem of realizing β-Ga by co-doping multiple elements. 2 O 3 When single crystals are p-doped, the material is prone to lattice distortion, forming an amorphous layer on the surface of the material, reducing the material quality and affecting device performance. This provides a new idea for the preparation of gallium oxide materials.

Description

Technical Field

[0001] The invention relates to the technical field of crystal materials, and specifically discloses a p-type gallium oxide material and a preparation method and application thereof. Background Art

[0002] Gallium oxide single crystal has multiple phases, among which the β phase is the most stable phase, and its melting point is about 1820℃, which means that β-Ga2O3 single crystal material can be grown by melt method. Compared with other ultra-wide bandgap semiconductor materials, β-Ga2O3 single crystal has the advantages of large size, low cost and high quality. The bandgap width of β-Ga2O3 single crystal is 4.9eV, the theoretical breakdown field strength is as high as 8MV / cm, and the Baliga figure of merit is more than ten times that of SiC and GaN. Therefore, gallium oxide-based power devices can theoretically have higher breakdown voltage and lower on-resistance, and have broad application prospects in rail transportation, high-voltage power transmission, new energy vehicles, aerospace and other fields.

[0003] At present, β-Ga2O3 single crystal materials have achieved N-type controllability through doping with elements such as Sn and Si, but there has been no breakthrough in p-type doping, which directly limits the development of gallium oxide-based power devices, making their withstand voltage and on-resistance far lower than the theoretical values. There are two reasons why p-type doping of β-Ga2O3 single crystal materials is difficult. One is that the activation energy of the doping element is high; the other is the self-binding effect in gallium oxide. Due to the extremely strong electronegativity of oxygen ions, holes are more stable when they form small polarons at the position of a single oxygen ion than when they form large-area free holes. The former has an energy lower than the latter by more than 500 meV, which means that the energy required to obtain free holes is equal to the acceptor ionization energy plus 500 meV. The above two factors make it difficult for shallow acceptors to exist in gallium oxide single crystal materials, and p-type conductivity cannot be achieved. This is a fatal defect for this material, which seriously limits its application in the high-ultra-high voltage field.

[0004] In view of the above-mentioned problem of p-type doping of β-Ga2O3 single crystal, the method of multi-element co-doping is currently used to solve it. First, a large amount of N element is doped into the β-Ga2O3 single crystal by ion implantation, and high-temperature annealing is performed to replace the oxygen element, reduce the electronegativity, and weaken the self-binding effect. Then, divalent metal elements are doped by ion implantation, and high-temperature annealing is performed to activate them, thereby obtaining free holes. However, the biggest problem of this method of achieving p-type conductivity of β-Ga2O3 single crystal by multi-element co-doping is that a large amount of N element and divalent metal element need to be doped by ion implantation. Ion implantation itself is to use high-energy ion beams to shoot into the target material. The ion beams collide with atoms or molecules in the material, so that the energy of the incident ions is gradually consumed and stays in the material, which will inevitably lead to lattice distortion in the material, and even form an amorphous layer on the surface, which seriously damages the material quality and affects the device performance. In addition, the band gap of gallium oxide is large, and the activation energy of divalent metal elements is very high, resulting in a high divalent metal doping concentration but a low effective hole concentration.

[0005] Based on this, the research and development of a p-type gallium oxide material is of great significance to the development of β-Ga2O3 single crystals. Summary of the invention

[0006] In view of the problem that when p-type doping of β-Ga2O3 single crystal is achieved by co-doping of multiple elements, the material is prone to lattice distortion, an amorphous layer is formed on the surface of the material, the material quality is reduced, and the device performance is affected, the present invention provides a p-type gallium oxide material and a preparation method and application thereof. The present invention constructs a divalent metal-doped gallium oxide nano-columnar structure, reduces the activation energy of effective holes, increases the concentration of effective holes, and successfully achieves the preparation of p-type gallium oxide material.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] A first aspect of the present invention provides a method for preparing a p-type gallium oxide material, comprising the following steps:

[0009] Step 1: sequentially growing a gallium oxide single crystal epitaxial layer and a mask layer on a gallium oxide substrate to obtain a pretreated gallium oxide material;

[0010] Step 2: imprinting a porous pattern on the surface of the pretreated gallium oxide material, and then etching away the gallium oxide single crystal epitaxial layer and the mask layer in the porous pattern to obtain a gallium oxide material with a porous surface;

[0011] Step 3: growing divalent metal-doped gallium oxide nanorods in the surface pores of the surface porous gallium oxide material, removing the mask, and obtaining a secondary treated gallium oxide material;

[0012] Step 4: Activate the secondary treated gallium oxide material to obtain a p-type gallium oxide material.

[0013] Since the gallium oxide single crystal has a double-chain structure, the two GaO6 octahedra are connected by GaO4 tetrahedra, and the presence of the divalent metal-doped gallium oxide nanocolumn structure is conducive to the spatial localization of holes, weakening the self-binding effect in gallium oxide, and the holes can be conducted along the chain structure to improve their mobility. At the same time, the divalent metal-doped gallium oxide nanocolumn structure can reduce the band gap of gallium oxide, thereby reducing the activation energy of effective holes, increasing the concentration of effective holes, and successfully realizing the preparation of p-type gallium oxide materials. More importantly, the present invention does not need to achieve p-type doping by ion implantation, but adopts an epitaxial growth method, which can effectively reduce the lattice distortion of the p-type layer and effectively avoid the generation of amorphous layer on the surface, which is conducive to the improvement of device performance. The technical solution of the present invention effectively solves the problem that when the p-type doping of β-Ga2O3 single crystal is achieved by co-doping of multiple elements, the material easily produces lattice distortion, forms an amorphous layer on the surface of the material, reduces the material quality, and affects the device performance. The method for preparing p-type gallium oxide materials of the present invention is simple, easy to operate, and low in cost, providing a new idea for the preparation of p-type gallium oxide materials.

[0014] Preferably, in step 1, the gallium oxide substrate is a gallium oxide single crystal substrate or a gallium oxide single crystal substrate with a Cu epitaxial layer loaded on the surface.

[0015] Preferably, in step 1, the gallium oxide single crystal epitaxial layer is grown by any one of metal organic compound chemical vapor deposition, hydride vapor phase epitaxy or molecular beam epitaxy.

[0016] Preferably, in step one, the mask layer is grown by atomic layer deposition or low pressure chemical vapor deposition.

[0017] Preferably, in step 1, the thickness of the gallium oxide single crystal epitaxial layer is 90nm-110nm.

[0018] Preferably, in step 1, the thickness of the mask layer is 15nm-25nm.

[0019] Preferably, in step 2, the pore area of ​​the porous pattern is 70 nm 2 -2000nm 2 , hole density is 20 / mm 2 -100pcs / mm 2 .

[0020] Preferably, in step 2, the etching uses a phosphoric acid solution with a mass fraction of 80%-90% as an etching solution.

[0021] Preferably, in step three, the growth method of the divalent metal-doped gallium oxide nanorods is any one of metal organic compound chemical vapor deposition, hydride vapor phase epitaxy or molecular beam epitaxy.

[0022] Preferably, in step three, the metal in the divalent metal-doped gallium oxide nanorods is any one of Mg, Zn, Cu or Fe.

[0023] Preferably, in step 3, the metal doping concentration in the divalent metal-doped gallium oxide nanorods is 1×10 19 Pieces / cm 3 -1×10 21 Pieces / cm 3 .

[0024] Preferably, in step three, the height of the divalent metal-doped gallium oxide nanorods is 90 nm-110 nm.

[0025] Preferably, in step three, a hydrofluoric acid solution with a mass fraction of 2%-3% is used to remove the mask.

[0026] Preferably, in step four, activation treatment is performed by high temperature annealing, light irradiation or radiation.

[0027] Further preferably, in step 4, the temperature of the high temperature annealing is 980° C.-1020° C., and the time of the high temperature annealing is 25 min-40 min.

[0028] A second aspect of the present invention provides a p-type gallium oxide material, which is prepared using the method for preparing the p-type gallium oxide material.

[0029] The third aspect of the present invention provides the use of the p-type gallium oxide material in the preparation of conductive materials in the ultra-high voltage field.

[0030] In summary, the present invention reduces the activation energy of effective holes, increases the concentration of effective holes, and successfully realizes the preparation of p-type gallium oxide materials by constructing a divalent metal-doped gallium oxide nanocolumnar structure in the gallium oxide epitaxial layer. The technical solution of the present invention effectively solves the problem that when p-type doping of β-Ga2O3 single crystal is achieved by co-doping with multiple elements, the material easily produces lattice distortion, forms an amorphous layer on the surface of the material, reduces the material quality, and affects the device performance, and provides a new idea for the preparation of p-type gallium oxide materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of the cross-sectional structure of the p-type gallium oxide material obtained in Example 1; wherein 1 is a Cu-doped gallium oxide nanorod structure, 2 is an unintentionally doped gallium oxide epitaxial layer, and 3 is a gallium oxide single crystal substrate;

[0032] Figure 2 This is a high-resolution X-ray diffraction test result diagram of the p-type gallium oxide material epitaxial layer obtained in Example 1. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Example 1

[0035] This embodiment provides a method for preparing a p-type gallium oxide material, which specifically includes the following contents:

[0036] Step 1: grow a 100 nm thick unintentionally doped gallium oxide single crystal epitaxial layer on a gallium oxide single crystal substrate using a molecular beam epitaxy method, wherein the vacuum in the molecular beam epitaxy growth chamber is as low as 6×10 -7 mbar, the evaporation temperature of the Ga metal evaporation source was set to 950 °C, and the flow rate intensity was 5 × 10 -6 mbar, the oxygen source is ozone, the flow rate is 1.5 sccm, the growth temperature is 750°C, the growth rate of the unintentionally doped gallium oxide single crystal epitaxial layer is 50nm / h, and the growth time is 2h; then, a SiO2 mask layer with a thickness of 20nm is deposited on the unintentionally doped gallium oxide single crystal epitaxial layer by atomic layer deposition technology to obtain a pretreated gallium oxide material;

[0037] Step 2: Use nanoimprinting to emboss a porous pattern on the surface of the pretreated gallium oxide material, with a pore area of ​​235.5 nm 2 , hole density is 70 / mm 2 ; Using a phosphoric acid solution with a mass fraction of 85%, at 150°C, the unintentionally doped gallium oxide epitaxial layer and mask layer in the pores are removed to expose the gallium oxide single crystal substrate and obtain a surface porous gallium oxide material;

[0038] Step 3: grow Cu-doped gallium oxide nanorods in the surface pores of the surface porous gallium oxide material by molecular beam epitaxy, and the vacuum in the molecular beam epitaxy growth chamber is as low as 6×10 -9 mbar, the evaporation temperature of the Ga metal evaporation source was set to 950 °C, and the velocity flow intensity was 8 × 10 -8mbar, the oxygen source is ozone, the flow rate is 0.5 sccm, the growth temperature is 800°C, the growth rate of the divalent metal-doped gallium oxide single crystal epitaxial layer is 20 nm / h, and the growth time is 5 h, so that the height of the divalent metal-doped gallium oxide nanocolumns in the circular holes is flush with the unintentionally doped gallium oxide single crystal epitaxial layer, the evaporation temperature of the Cu metal evaporation source is set to 1200°C, and the flow rate intensity is 2×10 -9 mbar, doping concentration is 5×10 19 Pieces / cm 3 ; Then, a hydrofluoric acid solution with a mass fraction of 2% is used to remove the mask to obtain a secondary treated gallium oxide material;

[0039] Step 4: heating the secondary treated gallium oxide material to 1000° C. and annealing for 30 minutes to obtain a p-type gallium oxide material.

[0040] Example 2

[0041] This embodiment provides a method for preparing a p-type gallium oxide material, which specifically includes the following contents:

[0042] Step 1: grow a 110 nm thick unintentionally doped gallium oxide single crystal epitaxial layer on a gallium oxide single crystal substrate using a molecular beam epitaxy method, wherein the vacuum in the molecular beam epitaxy growth chamber is as low as 6×10 -7 mbar, the evaporation temperature of the Ga metal evaporation source was set to 950 °C, and the flow rate intensity was 5 × 10 -6 mbar, the oxygen source is ozone, the flow rate is 1.5 sccm, the growth temperature is 750°C, the growth rate of the unintentionally doped gallium oxide single crystal epitaxial layer is 50nm / h, and the growth time is 2h; then, a SiO2 mask layer with a thickness of 25nm is deposited on the unintentionally doped gallium oxide single crystal epitaxial layer by atomic layer deposition technology to obtain a pretreated gallium oxide material;

[0043] Step 2: Use nanoimprinting to emboss a porous pattern on the surface of the pretreated gallium oxide material, with a pore area of ​​1600 nm 2 , hole density is 50 / mm 2 ; Using a phosphoric acid solution with a mass fraction of 90%, at 150°C, the unintentionally doped gallium oxide epitaxial layer and mask layer in the pores are removed to expose the gallium oxide single crystal substrate and obtain a surface porous gallium oxide material;

[0044] Step 3: grow Zn-doped gallium oxide nanorods in the surface pores of the surface porous gallium oxide material using molecular beam epitaxy, and the vacuum in the molecular beam epitaxy growth chamber is as low as 6×10 -9 mbar, the evaporation temperature of the Ga metal evaporation source was set to 950 °C, and the velocity flow intensity was 8 × 10 -8mbar, the oxygen source is ozone, the flow rate is 0.5 sccm, the growth temperature is 800°C, the growth rate of the divalent metal-doped gallium oxide single crystal epitaxial layer is 20 nm / h, and the growth time is 5 h, so that the height of the divalent metal-doped gallium oxide nanocolumns in the circular holes is flush with the unintentionally doped gallium oxide single crystal epitaxial layer, the evaporation temperature of the Zn metal evaporation source is set to 1200°C, and the flow rate intensity is 2×10 -9 mbar, doping concentration is 5×10 19 Pieces / cm 3 ; Then, a hydrofluoric acid solution with a mass fraction of 2% is used to remove the mask to obtain a secondary treated gallium oxide material;

[0045] Step 4: Raise the temperature of the secondary treated gallium oxide material to 1020° C. and perform annealing for 30 minutes to obtain a p-type gallium oxide material.

[0046] Example 3

[0047] This embodiment provides a method for preparing a p-type gallium oxide material, which specifically includes the following contents:

[0048] Step 1: grow a 90nm thick non-intentionally doped gallium oxide single crystal epitaxial layer on a gallium oxide single crystal substrate using a molecular beam epitaxy method, wherein the vacuum in the molecular beam epitaxy growth chamber is as low as 6×10 -7 mbar, the evaporation temperature of the Ga metal evaporation source was set to 950 °C, and the flow rate intensity was 5 × 10 -6 mbar, the oxygen source is ozone, the flow rate is 1.5 sccm, the growth temperature is 750°C, the growth rate of the unintentionally doped gallium oxide single crystal epitaxial layer is 50nm / h, and the growth time is 2h; then, a SiO2 mask layer with a thickness of 23nm is deposited on the unintentionally doped gallium oxide single crystal epitaxial layer by atomic layer deposition technology to obtain a pretreated gallium oxide material;

[0049] Step 2: Use nanoimprinting to emboss a porous pattern on the surface of the pretreated gallium oxide material, with a pore area of ​​1962.5 nm 2 , hole density is 20 / mm 2 ; Using a phosphoric acid solution with a mass fraction of 80%, at 150°C, the unintentionally doped gallium oxide epitaxial layer and mask layer in the pores are removed to expose the gallium oxide single crystal substrate and obtain a surface porous gallium oxide material;

[0050] Step 3: Using molecular beam epitaxy to grow Mg-doped gallium oxide nanorods in the surface pores of the surface porous gallium oxide material, the vacuum in the molecular beam epitaxy growth chamber is as low as 6×10 -9 mbar, the evaporation temperature of the Ga metal evaporation source was set to 950 °C, and the velocity flow intensity was 8 × 10 -8mbar, the oxygen source is ozone, the flow rate is 0.5 sccm, the growth temperature is 800°C, the growth rate of the divalent metal-doped gallium oxide single crystal epitaxial layer is 20 nm / h, and the growth time is 5 h, so that the height of the divalent metal-doped gallium oxide nanocolumns in the circular holes is flush with the unintentionally doped gallium oxide single crystal epitaxial layer, the evaporation temperature set by the Mg metal evaporation source is 1200°C, and the flow rate intensity is 2×10 -9 mbar, doping concentration is 5×10 19 Pieces / cm 3 ; Then, a hydrofluoric acid solution with a mass fraction of 2% is used to remove the mask to obtain a secondary treated gallium oxide material;

[0051] Step 4: raising the temperature of the secondary treated gallium oxide material to 980° C. and performing annealing treatment for 30 minutes to obtain a p-type gallium oxide material.

[0052] Example 4

[0053] This embodiment provides a method for preparing a p-type gallium oxide material, which specifically includes the following contents:

[0054] Step 1: grow a 95nm thick unintentionally doped gallium oxide single crystal epitaxial layer on a gallium oxide single crystal substrate using a molecular beam epitaxy method, wherein the vacuum in the molecular beam epitaxy growth chamber is as low as 6×10 -7 mbar, the evaporation temperature of the Ga metal evaporation source was set to 950 °C, and the flow rate intensity was 5 × 10 -6 mbar, the oxygen source is ozone, the flow rate is 1.5 sccm, the growth temperature is 750°C, the growth rate of the unintentionally doped gallium oxide single crystal epitaxial layer is 50nm / h, and the growth time is 2h; and then a SiO2 mask layer with a thickness of 17nm is deposited on the unintentionally doped gallium oxide single crystal epitaxial layer by atomic layer deposition technology to obtain a pretreated gallium oxide material;

[0055] Step 2: Use nanoimprinting to emboss a porous pattern on the surface of the pretreated gallium oxide material, with a pore area of ​​78.5 nm 2 , hole density is 100 / mm 2 ; Using a phosphoric acid solution with a mass fraction of 85%, at 150°C, the unintentionally doped gallium oxide epitaxial layer and mask layer in the pores are removed to expose the gallium oxide single crystal substrate and obtain a surface porous gallium oxide material;

[0056] Step 3: Using molecular beam epitaxy to grow Fe-doped gallium oxide nanorods in the surface pores of the surface porous gallium oxide material, the vacuum in the molecular beam epitaxy growth chamber is as low as 6×10 -9 mbar, the evaporation temperature of the Ga metal evaporation source was set to 950 °C, and the velocity flow intensity was 8 × 10 -8mbar, the oxygen source is ozone, the flow rate is 0.5 sccm, the growth temperature is 800°C, the growth rate of the divalent metal-doped gallium oxide single crystal epitaxial layer is 20 nm / h, and the growth time is 5 h, so that the height of the divalent metal-doped gallium oxide nanocolumns in the circular holes is flush with the unintentionally doped gallium oxide single crystal epitaxial layer, the evaporation temperature of the Fe metal evaporation source is set to 1200°C, and the flow rate intensity is 2×10 -9 mbar, doping concentration is 5×10 19 Pieces / cm 3 ; Then, a hydrofluoric acid solution with a mass fraction of 2% is used to remove the mask to obtain a secondary treated gallium oxide material;

[0057] Step 4: heating the secondary treated gallium oxide material to 1010° C. and performing annealing for 30 minutes to obtain a p-type gallium oxide material.

[0058] Comparative Example 1

[0059] This comparative example provides a method for preparing a p-type gallium oxide material, which is different from Example 1 in that step 2 is omitted, and a metal-doped gallium oxide nano-columnar structure is directly grown on the surface of the gallium oxide single crystal epitaxial layer, specifically including the following contents:

[0060] Step 1: grow a 100 nm thick unintentionally doped gallium oxide single crystal epitaxial layer on a gallium oxide single crystal substrate using a molecular beam epitaxy method, wherein the vacuum in the molecular beam epitaxy growth chamber is as low as 6×10 -7 mbar, the evaporation temperature of the Ga metal evaporation source was set to 950 °C, and the flow rate intensity was 5 × 10 -6 mbar, the oxygen source is ozone, the flow rate is 1.5 sccm, the growth temperature is 750°C, the growth rate of the unintentionally doped gallium oxide single crystal epitaxial layer is 50 nm / h, and the growth time is 2 hours; the pretreated gallium oxide material is obtained;

[0061] Step 2: Cu-doped gallium oxide nanorods are grown on the surface of the pretreated gallium oxide material using molecular beam epitaxy. The vacuum in the molecular beam epitaxy growth chamber is as low as 6×10 -9 mbar, the evaporation temperature of the Ga metal evaporation source was set to 950 °C, and the velocity flow intensity was 8 × 10 -8 mbar, the oxygen source is ozone, the flow rate is 0.5 sccm, the growth temperature is 800°C, the growth rate of the bivalent metal-doped gallium oxide single crystal epitaxial layer is 20 nm / h, the growth time is 5 h, the evaporation temperature set by the Cu metal evaporation source is 1200°C, and the flow rate is 2×10 -9 mbar, doping concentration is 5×10 19 Pieces / cm 3 ; Obtaining secondary processed gallium oxide material;

[0062] Step 3: heating the secondary treated gallium oxide material to 1000° C. and annealing for 30 minutes to obtain a p-type gallium oxide material.

[0063] Comparative Example 2

[0064] This comparative example provides a method for preparing a gallium oxide material, which is different from Example 1 in that a metal-doped gallium oxide nanocolumnar structure is directly grown on a gallium oxide single crystal substrate, specifically including the following contents:

[0065] Step 1: Cu-doped gallium oxide nanorods are grown on gallium oxide single crystal substrates using molecular beam epitaxy. The vacuum in the molecular beam epitaxy growth chamber is as low as 6×10 -9 mbar, the evaporation temperature of the Ga metal evaporation source was set to 950 °C, and the velocity flow intensity was 8 × 10 -8 mbar, the oxygen source is ozone, the flow rate is 0.5 sccm, the growth temperature is 800°C, the growth rate of the divalent metal-doped gallium oxide single crystal epitaxial layer is 20 nm / h, and the growth time is 5 h, so that the height of the divalent metal-doped gallium oxide nanocolumns in the circular holes is flush with the unintentionally doped gallium oxide single crystal epitaxial layer, the evaporation temperature of the Cu metal evaporation source is set to 1200°C, and the flow rate intensity is 2×10 -9 mbar, doping concentration is 5×10 19 Pieces / cm 3 ; Gallium oxide materials can be processed once;

[0066] Step 2: raising the temperature of the secondary treated gallium oxide material to 1000° C. and performing annealing treatment for 30 minutes to obtain a p-type gallium oxide material.

[0067] In order to demonstrate the technical effect of the present invention, the present invention uses the HL5500 Hall effect tester to characterize the electrical properties of the gallium oxide materials obtained in Examples 1-4 and the gallium oxide materials obtained in Comparative Examples 1-2. The specific data are shown in Table 1. The present invention also performs a high-resolution X-ray diffraction test on the p-type gallium oxide material obtained in Example 1. The results are shown in Table 1. Figure 2 As shown. Figure 2 It can be seen that the half-width at half maximum of the rocking curve of the p-type gallium oxide obtained in Example 1 is less than 50 arc seconds, indicating that the epitaxial layer of the p-type gallium oxide has good crystalline quality.

[0068] Table 1 Electrical properties test results of gallium oxide materials obtained in Examples 1-4 and Comparative Examples 1-2

[0069]

[0070] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a p-type gallium oxide material, characterized in that: The steps include: Step 1: sequentially growing a gallium oxide single crystal epitaxial layer and a mask layer on a gallium oxide substrate to obtain a pretreated gallium oxide material; Step 2: imprinting a porous pattern on the surface of the pretreated gallium oxide material, and then etching away the gallium oxide single crystal epitaxial layer and the mask layer in the porous pattern to obtain a gallium oxide material with a porous surface; Step 3: growing divalent metal-doped gallium oxide nanorods in the surface pores of the surface porous gallium oxide material, removing the mask, and obtaining a secondary treated gallium oxide material; Step 4: activating the secondary treated gallium oxide material to obtain a p-type gallium oxide material; In step 2, the pore area of ​​the porous pattern is 70 nm 2 -2000nm 2 , hole density is 20 / mm 2 -100pcs / mm 2 ; In step 3, the divalent metal in the divalent metal-doped gallium oxide nanorods is any one of Mg, Zn, Cu or Fe; In step 3, the metal doping concentration in the divalent metal-doped gallium oxide nanorods is 1×10 19 Pieces / cm 3 -1×10 21 Pieces / cm 3 .

2. The method for preparing a p-type gallium oxide material according to claim 1, characterized in that: In step 1, the gallium oxide substrate is a gallium oxide single crystal substrate or a gallium oxide single crystal substrate with a Cu epitaxial layer on the surface; and / or In step 1, the gallium oxide single crystal epitaxial layer is grown by any one of metal organic compound chemical vapor deposition, hydride vapor phase epitaxy or molecular beam epitaxy; and / or In step 1, the mask layer is grown by atomic layer deposition or low pressure chemical vapor deposition.

3. The method for preparing a p-type gallium oxide material according to claim 1, wherein: In step 1, the thickness of the gallium oxide single crystal epitaxial layer is 90nm-110nm; and / or In step 1, the thickness of the mask layer is 15nm-25nm.

4. The method for preparing a p-type gallium oxide material according to claim 1, characterized in that: In step 2, the etching uses a phosphoric acid solution with a mass fraction of 80%-90% as an etching solution.

5. The method for preparing a p-type gallium oxide material according to claim 1, characterized in that: In step three, the growth method of the divalent metal-doped gallium oxide nanorods is any one of metal organic compound chemical vapor deposition, hydride vapor phase epitaxy or molecular beam epitaxy.

6. The method for preparing a p-type gallium oxide material according to claim 1, characterized in that: In step 3, the height of the divalent metal-doped gallium oxide nanorods is 90 nm-110 nm; and / or In step three, a hydrofluoric acid solution with a mass fraction of 2% to 3% is used to remove the mask.

7. The method for preparing a p-type gallium oxide material according to claim 1, characterized in that: In step 4, activation treatment is performed by high temperature annealing, light irradiation or radiation.

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