阅读说明：本技术 一种高阻氧化镓晶体及其制备方法与应用 (High-resistance gallium oxide crystal and preparation method and application thereof ) 是由 唐慧丽 李志伟 刘波 徐军 罗平 吴锋 王庆国 张超逸 于 2021-07-21 设计创作，主要内容包括：本发明涉及一种高阻氧化镓晶体及其制备方法与应用,所述高阻氧化镓晶体的分子式为β-(Ga-(1-x)Al-(x))-(2)O-(3),其中x的取值范围为0.07≤x≤0.3,采用包括光学浮区法、提拉法、导模法或下降法的熔体生长方法制备得到。与现有技术相比,本发明提供的掺铝高阻氧化镓晶体的电阻率≥10～(9)Ω·cm,晶体结晶质量高,基于该高阻氧化镓晶体制备的辐射探测器具有制作工艺简单、暗电流小、光暗电流比高、响应速度快、灵敏度高、信噪比高、能量分辨率好等优点。(The invention relates to a high-resistance gallium oxide crystal and a preparation method and application thereof, wherein the molecular formula of the high-resistance gallium oxide crystal is beta- (Ga) 1‑x Al x ) 2 O 3 Wherein x is not less than 0.07 and not more than 0.3, and the formula includesThe crystal is prepared by a melt growth method of an optical floating zone method, a pulling method, a die guiding method or a descent method. Compared with the prior art, the resistivity of the aluminum-doped high-resistance gallium oxide crystal provided by the invention is more than or equal to 10 9 Omega cm, high crystal crystallization quality, and the radiation detector prepared based on the high-resistance gallium oxide crystal has the advantages of simple manufacturing process, small dark current, high light-dark current ratio, high response speed, high sensitivity, high signal-to-noise ratio, good energy resolution ratio and the like.)

1. The high-resistance gallium oxide crystal is characterized in that the molecular formula of the high-resistance gallium oxide crystal is beta- (Ga)_1-xAl_x)₂O₃Wherein x isThe value range is that x is more than or equal to 0.07 and less than or equal to 0.3.

2. The high-resistivity gallium oxide crystal according to claim 1, wherein x is 0.07, 0.08, 0.1, 0.12, 0.15, 0.3.

3. The method for preparing high-resistance gallium oxide crystal according to claim 1 or 2, wherein the high-resistance gallium oxide crystal is prepared by a melt growth method comprising an optical float zone method, a Czochralski method, a guided mode method or a descent method.

4. The method for preparing high-resistance gallium oxide crystal according to claim 3, comprising the following steps:

(1) taking Ga₂O₃Powder and Al₂O₃Powder, accurately weighing and uniformly mixing the raw material powder according to a molecular formula, performing compression molding in a hydraulic or isostatic pressing mode, and performing high-temperature solid-phase sintering to synthesize the aluminum-doped gallium oxide polycrystal material;

(2) loading polycrystalline raw materials into an iridium crucible or a platinum-rhodium crucible or fixing the polycrystalline raw materials on an upper rotating rod of an optical float zone furnace;

(3) fixing the directional seed crystal on a seed crystal rod;

(4) and growing the aluminum-doped gallium oxide crystal by adopting an optical floating zone method, a pulling method, a mode guiding method and a descending method.

5. The method for preparing high-resistivity gallium oxide crystal according to claim 4, wherein the Ga in the step (1)₂O₃The purity of the powder is preferably 4N-6N, Al₂O₃The powder purity is preferably 4N-5N.

6. The method for preparing a high-resistance gallium oxide crystal according to claim 4, wherein in the step (2), when the Czochralski method, the mold-guiding method or the descent method is adopted, an iridium or platinum-rhodium crucible, carbon dioxide or a mixed atmosphere consisting of carbon dioxide and argon gas is adopted; when the optical floating zone method is adopted for growth, an air atmosphere or a pure oxygen atmosphere is adopted, and the gas flow rate is preferably 1-5L/min.

7. The use of a high-resistivity gallium oxide crystal according to claim 1, wherein the high-resistivity gallium oxide crystal is used for manufacturing a semiconductor radiation detector.

8. The use of a high-resistivity gallium oxide crystal according to claim 7, wherein the radiation detector uses a double-sided symmetrical electrode structure, and the double-sided symmetrical electrode is a Ti/Au double-layer metal electrode.

9. The use of a high-resistivity gallium oxide crystal according to claim 8, wherein the Ti layer has a thickness of 5-50nm, the Au layer has a thickness of 50-100nm, the electrode has a circular or rectangular shape, and the electrode area is 1-30mm²。

10. The use of the high-resistivity gallium oxide crystal according to claim 9, wherein the high-resistivity gallium oxide crystal is cut and double-sided chemically mechanical polished to a wafer thickness of 0.4-4 mm.

Technical Field

The invention belongs to the field of semiconductor crystal materials and nuclear radiation detectors, and particularly relates to a high-resistance gallium oxide crystal and a preparation method and application thereof.

Background

Gallium oxide (. beta. -Ga)₂O₃) The crystal is a novel ultra-wide bandgap semiconductor material, has the advantages of large bandgap (4.8 eV), high theoretical breakdown field strength (8MV/cm), strong radiation resistance and the like, and has attracted much attention in recent years. Unintentionally doped gallium oxide crystals have a low resistivity due to the shallow donors formed in the crystal by impurities such as Si, Sn, Ge, etc. remaining in the raw material, resulting in a crystal with a certain concentration of free electrons. The X-ray radiation detection device prepared by using the unintentionally doped gallium oxide crystal has higher dark current, reduces the core parameters of the device such as light-dark current ratio, sensitivity and the like, and seriously influences the use of the detection device (such as 'Schottky X-ray detectors based on a bulk beta-Ga')₂O₃ substrate”,Applied Physics Letters 112,103502,2018)。

In the field of nuclear radiation detection, in order to make a semiconductor detection device have excellent performances such as high dark current ratio, high sensitivity, high signal-to-noise ratio, high energy resolution and the like, a high-resistance semiconductor material is required to be used for reducing the dark current of the device and improving the detection limit. For gallium oxide crystals, magnesium ions, iron ions, calcium ions and zinc ions doped with the gallium oxide crystal can play an acceptor compensation role, and the concentration of free electrons in the crystal is reduced, so that gallium oxide crystals with higher resistivity or semi-insulation are obtained (patent CN 109537055 a). However, these commonly used acceptor-compensated doped ions and gallium do not belong to the same group of elements, the difference of electronic structure is large, and after the impurity elements are doped, the lattice of the gallium oxide crystal is greatly distorted, which affects the crystallization quality of the high-resistance gallium oxide crystal.

The patent CN 113035999A discloses an Al-doped gallium oxide X-ray detector and a preparation method thereof, the carrier concentration in an Al-doped gallium oxide single crystal is reduced in a mode of high-temperature annealing at 1250-1600 ℃ in air or oxygen atmosphere, and a high-resistance gallium oxide crystal is not obtained by adjusting the doping concentration of Al ions; this patent uses the X-ray detector of interdigital electrode preparation because the electric field depth is less than X ray's penetration depth far away, and most photogenerated electron hole pair can't be collected by the electrode, causes the carrier collection efficiency low, and the photocurrent of detector is not high, and the surface defect of crystal can produce a large amount of leakage currents moreover, leads to the dark current of detector to improve, is unfavorable for the device and is applied to low dose rate and surveys.

Disclosure of Invention

The invention aims to overcome the defects that the high-resistance gallium oxide crystal obtained by doping the hetero-element easily causes larger lattice distortion, the crystal quality is lower, and the electron mobility is reduced, and provides the high-resistance gallium oxide crystal and the preparation method and the application thereof.

The resistivity of the aluminum-doped high-resistance gallium oxide crystal provided by the invention is more than or equal to 10⁹Omega cm, high crystal crystallization quality, and the radiation detector prepared based on the high-resistance gallium oxide crystal has the advantages of simple manufacturing process, small dark current, high light-dark current ratio, high response speed, high sensitivity, high signal-to-noise ratio, good energy resolution ratio and the like.

The purpose of the invention is realized by the following technical scheme:

a high-resistance gallium oxide crystal with a molecular formula of beta- (Ga)_1-xAl_x)₂O₃Wherein the value range of x is more than or equal to 0.07 and less than or equal to 0.3, and the value range of x is used for obtaining high oxygen resistance with excellent performanceGallium oxide crystals have important influence, and when the value of x is lower than 0.07, the gallium oxide crystals have higher carrier concentration and lower resistivity; when the value of x is more than 0.3, the quality of the gallium oxide crystal is seriously deteriorated.

The aluminum and the gallium belong to the same group elements, have quite similar electronic structures, and the ionic radii are close, so that the aluminum ions cannot cause larger lattice distortion of the gallium oxide crystal when being doped, and therefore, the aluminum ions with higher concentration can be doped in the gallium oxide crystal. The principle of increasing the resistivity of gallium oxide crystals by doping aluminum ions is as follows: the valence band top of the gallium oxide crystal is determined by O2p state, the conduction band bottom is determined by Ga4s state, and after doping aluminum ions, the valence band spectrum test obtains beta- (Ga)_1-xAl_x)₂O₃The top position of the valence band of the crystal is not intentionally doped with beta-Ga₂O₃The crystals are kept uniform, beta- (Ga)_1-xAl_x)₂O₃The valence band top of the crystal is still determined by the state of O2p, so that the doping of aluminum ions does not cause significant changes in the position of the valence band top of the gallium oxide crystal. However, beta- (Ga)_1-xAl_x)₂O₃The conduction band of the crystal is influenced by the Al3s state, and the conduction band bottom moves away from the valence band, so that beta- (Ga) is generated_1-xAl_x)₂O₃The forbidden band width of the crystal is increased, resulting in beta- (Ga)_1-xAl_x)₂O₃The distance from the bottom of the crystal conduction band to the donor level is increased, that is, the depth of the trap of the donor level is increased, and the capability of the donor level to supply electrons to the conduction band is suppressed, so that beta- (Ga)_1-xAl_x)₂O₃The free electron concentration of the crystal is greatly reduced, and the resistivity of the gallium oxide crystal is obviously improved. The high-resistance gallium oxide crystal provided by the invention has the resistivity of up to 10 at room temperature⁹-10¹²Omega cm, and the forbidden band width is 4.9eV-5.3 eV.

The preparation method of the high-resistance gallium oxide crystal can adopt melt growth methods such as an optical floating zone method, a pulling method, a mold guiding method, a descent method and the like, and the preferable preparation steps are as follows:

(1) taking Ga₂O₃Powder and Al₂O₃Powder, accurately weighing the above raw material powder according to molecular formulaWeighing and uniformly mixing, pressing and molding by adopting a hydraulic or isostatic pressing mode, and synthesizing the aluminum-doped gallium oxide polycrystal material by high-temperature solid-phase sintering;

(2) polycrystalline raw materials are loaded into an iridium crucible or a platinum-rhodium crucible or are fixed on an upper rotating rod of an optical float zone furnace.

(3) And fixing the directional seed crystal on the seed crystal rod.

(4) And growing the aluminum-doped gallium oxide crystal by adopting an optical floating zone method, a pulling method, a mode guiding method and a descending method.

Ga described in step (1)₂O₃The purity of the powder is preferably 4N-6N, Al₂O₃The purity of the powder is preferably 4N-5N, the content of impurities in the high-purity raw material is less, and the problems of reduction of the resistivity of crystals, poor crystal quality and the like caused by the impurities can be avoided.

When the pulling method, the guide die method or the descending method is adopted in the step (2), an iridium or platinum-rhodium alloy crucible and carbon dioxide or a mixed atmosphere consisting of carbon dioxide and argon are adopted; when the optical floating zone method is adopted for growth, an air atmosphere or a pure oxygen atmosphere is adopted, and the gas flow rate is preferably 1-5L/min.

The invention also provides an application of the high-resistance gallium oxide crystal in a semiconductor radiation detection device, and a radiation detector prepared based on the high-resistance gallium oxide crystal adopts a double-sided symmetrical electrode structure.

The high-resistance gallium oxide crystal is cut and subjected to double-sided chemical mechanical polishing, the thickness of a wafer is 0.4-4mm, and the wafer thickness is less than 0.4mm, so that high-energy rays cannot be completely absorbed, and the photocurrent of a radiation detector is reduced; the wafer thickness is larger than 4mm, so that the capture probability in the carrier transport process is increased, the carrier collection efficiency of the detector is reduced, and the photocurrent is reduced.

The double-sided symmetrical electrode of the detector is a Ti/Au double-layer metal electrode, the thickness of the Ti layer is 5-50nm, the thickness of the Au layer is 50-100nm, the electrode is circular or rectangular, and the area of the electrode is 1-30mm²。

Compared with the prior art, the invention has the following advantages:

(1) compared with the doping of iron, magnesium and other foreign elements, the doping of aluminum ions can further increase the forbidden bandwidth while improving the resistivity of the gallium oxide crystal, and can not cause serious distortion of the crystal lattice of the gallium oxide crystal due to aluminum doping, so that the obtained high-resistance gallium oxide crystal has high crystal quality.

(2) Compared with the prior art patent CN 113035999A, the invention realizes the high resistance of the gallium oxide crystal by limiting the Al ion doping concentration to reduce the back bottom carrier concentration of the gallium oxide crystal; compared with a low-resistivity gallium oxide crystal, the semiconductor radiation detector prepared by the high-resistivity gallium oxide crystal provided by the invention has the remarkable advantages of low dark current, high optical dark current ratio, high response speed (both the rise time and the fall time are less than 0.05s) and the like, the detection sensitivity is far higher than that of a commercial amorphous selenium X-ray detector, and the energy resolution is equivalent to that of a tellurium-zinc-cadmium gamma ray detector.

(3) Compared with the radiation detector adopting the interdigital electrode in the prior art patent CN 113035999A, the radiation detector adopting the double-sided electrode has the advantages of simple device preparation process, capability of completely absorbing high-energy rays, high carrier collection efficiency, small influence of surface leakage current and the like.

Drawings

FIG. 1 shows example 1. beta. - (Ga)_0.85Al_0.15)₂O₃And cutting the polished crystal photo.

FIG. 2 shows β - (Ga)_1-xAl_x)₂O₃And x is 0.05, 0.1, 0.15 transmission spectrum of the crystal.

FIG. 3 is a view of beta- (Ga)_1-xAl_x)₂O₃And x is the forbidden band width spectrum of 0.05, 0.1 and 0.15 crystals.

FIG. 4 shows β - (Ga)_1-xAl_x)₂O₃Energy band diagram of the crystal.

FIG. 5 is β - (Ga)_1-xAl_x)₂O₃Crystal resistivity versus x.

FIG. 6 shows a graph based on β - (Ga)_1-xAl_x)₂O₃A structure diagram of a radiation detection device for a crystal;

1-Au, 2-Ti, 3-beta- (Ga) in FIG. 6_1-xAl_x)₂O₃Crystal, 4-Ti, 5-Au.

FIG. 7 shows a graph based on β - (Ga)_0.85Al_0.15)₂O₃Dark current and photocurrent of a radiation detector of the crystal.

FIG. 8 shows a graph based on β - (Ga)_0.85Al_0.15)₂O₃The time response of a radiation detector of a crystal to X-rays at different voltages.

FIG. 9 shows β - (Ga)_0.95Al_0.05)₂O₃I-V curve of the crystal.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments.

Example 1:

growth of beta- (Ga) by optical floating zone method_0.85Al_0.15)₂O₃And (4) crystals.

Ga is weighed according to the molar ratio of 0.85:0.15₂O₃Powder and Al₂O₃The powder was ground for 60 minutes to mix the powder uniformly, the uniformly mixed powder was charged into a long rubber tube using a funnel to prepare a raw material rod, the raw material rod was pressed using a cold isostatic press under a pressure of 50MPa, and the raw material rod was sintered in a muffle furnace at 1450 ℃ in air for 20 hours to prepare a ceramic-like raw material rod. Growing crystals in an optical floating zone furnace in a flowing air atmosphere, mounting the raw material rod on an upper rotating rod,<010>the seed crystal in the direction is fixed on the lower rotating rod, the voltage is slowly increased to heat the seed crystal and the raw material rod, the growth speed of the crystal is 3mm/h, the rotating speed is 14rpm, the air flow rate is 3L/min, the temperature is slowly reduced to the room temperature after the growth is finished, the crystal is taken out, and the crystal is colorless and transparent and has no cracks. Cutting and polishing the crystal to obtain 5 × 5 × 1mm³As shown in fig. 1. (Ga)_0.85Al_0.15)₂O₃Diffraction peak of crystal XRD pattern and beta-Ga₂O₃The standard cards are consistent. Beta- (Ga)_1-xAl_x)₂O₃The transmission spectrum of 0.05, 0.1 and 0.15 crystal is shown in fig. 2, free electrons cause plasma reflection, and the transmission of infrared band is reducedExcess, beta- (Ga)_0.85Al_0.15)₂O₃The crystal has no obvious absorption in the infrared band, which indicates that the free electron concentration of the crystal is extremely low. As can be seen from FIG. 3, β - (Ga)_0.85Al_0.15)₂O₃The forbidden bandwidth of the crystal is 5.11eV, and the forbidden bandwidth of the gallium oxide crystal is increased after aluminum doping. Beta- (Ga)_0.85Al_0.15)₂O₃The valence band spectrum test of the crystal obtains the top position of the valence band and beta-Ga₂O₃The crystals remained consistent, indicating that the aluminum doping did not alter the beta-Ga₂O₃The position of the top of the valence band of the crystal. After doping with aluminium ions, beta-Ga₂O₃The top of the conduction band of the crystal moves up, away from the original shallow donor, and the ability of the donor level to donate a free electron to the conduction band at room temperature is suppressed. FIG. 4 shows β - (Ga)_1-xAl_x)₂O₃Band diagram of crystal, wherein E_cIs the conduction band energy level, E_vIs the valence band energy level, E_DIs a donor level, E_FAt Fermi level, beta- (Ga)_0.85Al_0.15)₂O₃The position of the conduction band bottom of the crystal is higher than that of beta-Ga₂O₃Crystal, donor level ratio beta-Ga₂O₃Deeper in the crystal. FIG. 5 shows resistivity measurements of beta- (Ga)_{1- x}Al_x)₂O₃Plot of crystal resistivity against x, beta- (Ga)_0.85Al_0.15)₂O₃The resistivity of the crystal was 1.5X 10¹²Omega cm. Preparation of a catalyst based on beta- (Ga)_0.85Al_0.15)₂O₃A radiation detector of a crystal is characterized in that square Ti/Au electrodes are respectively deposited on the upper surface and the lower surface of the crystal, the thickness of the square Ti/Au electrodes is 20nm/50nm, the side length of the square Ti/Au electrodes is 3mm, and the structure of the detector is shown in figure 6. The radiation detector was tested for its detection of X-rays using an X-ray source with a tube voltage of 50 kV. FIG. 7 shows that the photo-dark current ratio of the detector is as high as 700 when the X-ray dose rate is 0.15Gy/s and the device voltage is 200V. FIG. 8 shows the response of the detector under different voltages when the X-ray dose rate is 9.8 μ Gy/s, and the result shows that the response speed of the detector is extremely fast, and the rise time and the fall time are both less than 0.05 s; when the voltage is 350V, the detector pairThe detection sensitivity of X-ray was 851. mu.C Gy^-1cm^-242 times the sensitivity of a commercial amorphous selenium X-ray detector; the signal-to-noise ratio of the detectors under all voltages is higher than 20, and the practical requirements are met. The response of the detector to gamma rays is tested by using a gamma ray source such as cesium-137, cobalt-60 and the like, and the energy resolution of the detector is equivalent to that of a cadmium zinc telluride gamma ray detector. The above results show that the beta- (Ga) -based alloy is based on_0.85Al_0.15)₂O₃The radiation detector of the crystal shows excellent detection performance to X-ray and gamma ray.

Comparative example 1:

growth of beta- (Ga) by optical floating zone method_0.95Al_0.05)₂O₃And (4) crystals.

Ga is weighed according to the molar ratio of 0.95:0.05₂O₃Powder and Al₂O₃The powder was ground for 60 minutes to mix the powder uniformly, the uniformly mixed powder was charged into a long rubber tube using a funnel to prepare a raw material rod, the raw material rod was pressed using a cold isostatic press under a pressure of 50MPa, and the raw material rod was sintered in a muffle furnace at 1450 ℃ in air for 20 hours to prepare a ceramic-like raw material rod. Growing crystals in an optical floating zone furnace in a flowing air atmosphere, mounting the raw material rod on an upper rotating rod,<010>the seed crystal in the direction is fixed on the lower rotating rod, the voltage is slowly increased to heat the seed crystal and the raw material rod, the growth speed of the crystal is 3mm/h, the rotation speed is 14rpm, the air flow rate is 3L/min, the temperature is slowly reduced to the room temperature after the growth is finished, and the crystal is taken out. Cutting and polishing the crystal to obtain 5 × 5 × 1mm³The wafer of (1). As shown in FIG. 2, β - (Ga)_0.95Al_0.05)₂O₃The crystal has obvious infrared absorption, which indicates that the crystal has higher free electron concentration. FIG. 9 shows β - (Ga)_0.95Al_0.05)₂O₃The I-V curve of the crystal can reach larger current at low voltage, so the resistivity of the crystal is lower. Based on beta- (Ga)_0.95Al_0.05)₂O₃The radiation detector made of the crystal has larger dark current.

Example 2:

optical floating zone method for growing beta-(Ga_0.9Al_0.1)₂O₃And (4) crystals.

Ga is weighed according to the molar ratio of 0.9:0.1₂O₃Powder and Al₂O₃The powder was ground for 60 minutes to mix the powder uniformly, the uniformly mixed powder was charged into a long rubber tube using a funnel to prepare a raw material rod, the raw material rod was pressed using a cold isostatic press under a pressure of 50MPa, and the raw material rod was sintered in a muffle furnace at 1450 ℃ in air for 20 hours to prepare a ceramic-like raw material rod. Growing crystal in an optical floating zone furnace in flowing oxygen atmosphere, mounting the raw material rod on an upper rotating rod,<010>the seed crystal in the direction is fixed on the lower rotating rod, the voltage is slowly increased to heat the seed crystal and the raw material rod, the growth speed of the crystal is 4mm/h, the rotating speed is 14rpm, the flow rate of oxygen is 1L/min, the temperature is slowly reduced to the room temperature after the growth is finished, and the crystal is taken out. Cutting and polishing the crystal to obtain 5 × 5 × 1mm³The wafer of (1). As shown in FIG. 2, β - (Ga)_0.9Al_0.1)₂O₃The crystal has no obvious infrared absorption, and the forbidden band width is 4.96 eV. As shown in FIG. 5, the resistivity test gave β - (Ga)_0.9Al_0.1)₂O₃The resistivity of the crystal was 3.8X 10¹¹Omega cm. Preparation of a catalyst based on beta- (Ga)_0.9Al_0.1)₂O₃The radiation detector of the crystal has the detection sensitivity of 283 mu CGy to X-rays at the voltage of 200V^-1cm^-2。

Example 3:

growth of beta- (Ga) by optical floating zone method_0.7Al_0.3)₂O₃And (4) crystals.

Ga is weighed according to the molar ratio of 0.7:0.3₂O₃Powder and Al₂O₃The powder was ground for 60 minutes to mix the powder uniformly, the uniformly mixed powder was charged into a long rubber tube using a funnel to prepare a raw material rod, the raw material rod was pressed using a cold isostatic press under a pressure of 50MPa, and the raw material rod was sintered in a muffle furnace at 1450 ℃ in air for 20 hours to prepare a ceramic-like raw material rod. Growing crystals in an optical floating zone furnace in a flowing air atmosphere, mounting the raw material rod on an upper rotating rod,<010>the directional seed crystal is fixed on the lower rotating rod and is slowly rotatedSlowly raising the voltage to heat the seed crystal and the raw material rod, wherein the growth speed of the crystal is 2mm/h, the rotation speed is 14rpm, the air flow rate is 5L/min, slowly cooling to room temperature after the growth is finished, and taking out the crystal. Cutting and polishing the crystal to obtain 5 × 5 × 1mm³The wafer of (1). Beta- (Ga)_0.7Al_0.3)₂O₃The crystal is colorless and transparent and has no crack. As shown in FIG. 5, the resistivity test gave β - (Ga)_0.7Al_0.3)₂O₃The resistivity of the crystal was 2.5X 10¹²Omega cm. Preparation of a catalyst based on beta- (Ga)_0.7Al_0.3)₂O₃The radiation detector of the crystal has the detection sensitivity of 721 mu C Gy to X-rays at the voltage of 350V^-1cm^-2。

Comparative example 2:

growth of beta- (Ga) by optical floating zone method_0.68Al_0.32)₂O₃And (4) crystals.

Ga is weighed according to the molar ratio of 0.68:0.32₂O₃Powder and Al₂O₃The powder was ground for 60 minutes to mix the powder uniformly, the uniformly mixed powder was charged into a long rubber tube using a funnel to prepare a raw material rod, the raw material rod was pressed using a cold isostatic press under a pressure of 50MPa, and the raw material rod was sintered in a muffle furnace at 1450 ℃ in air for 20 hours to prepare a ceramic-like raw material rod. Growing crystals in an optical floating zone furnace in a flowing air atmosphere, mounting the raw material rod on an upper rotating rod,<010>the directional seed crystal is fixed on the lower rotating rod, the voltage is slowly increased to heat the seed crystal and the raw material rod, the growth speed of the crystal is 2mm/h, the rotating speed is 14rpm, the air flow rate is 5L/min, the temperature is slowly reduced to the room temperature after the growth is finished, the crystal is taken out, and the crystal is turbid and opaque and has cracks, and the quality of the crystal is poor.

Example 4:

growth of beta- (Ga) by descent_0.88Al_0.12)₂O₃And (4) crystals.

Ga is weighed according to the molar ratio of 0.88:0.12₂O₃Powder and Al₂O₃Grinding the powder for 60 min to mix the powder uniformly, pressing the uniformly mixed powder to form by using a hydraulic press, putting the raw materials into the pressSintering the mixture in a muffle furnace at 1450 ℃ for 20h to prepare the polycrystalline material. Putting the raw materials into a platinum-rhodium crucible for use<010>Directional seed crystal, vacuumizing to 5Pa, and charging CO₂Heating to 1.03MPa until the raw materials are completely melted, keeping the temperature for 2 hours to ensure that the crucible slowly descends at the speed of 0.5mm/h, slowly cooling to room temperature after the growth is finished, and taking out the crystal. Cutting and polishing the crystal to obtain 5 × 5 × 1mm³The wafer of (1). As shown in FIG. 5, the resistivity test gave β - (Ga)_0.88Al_0.12)₂O₃The resistivity of the crystal was 9.1X 10¹¹Omega cm. Preparation of a catalyst based on beta- (Ga)_0.88Al_0.12)₂O₃The radiation detector of the crystal has the detection sensitivity of 379 mu C Gy to X-rays at the voltage of 200V^-1cm^-2。

Example 5:

czochralski method for growing beta- (Ga)_0.93Al_0.07)₂O₃And (4) crystals.

Ga is weighed according to the molar ratio of 0.93 to 0.07₂O₃Powder and Al₂O₃Grinding the powder for 60 minutes to uniformly mix the powder, pressing the uniformly mixed powder into cakes by using a hydraulic press, and sintering the raw materials in a muffle furnace at 1450 ℃ in air for 20 hours to prepare a polycrystalline material. Putting the raw materials into an iraurita crucible, and putting<010>The directional seed crystal is fixed in the seed crystal rod clamp. Vacuumizing to 5Pa according to the ratio of Ar to CO₂Filling mixed gas to 1.04MPa according to the proportion of 2:8, heating until the raw material is completely melted, descending the seed crystal to be contacted with the melt, pulling the seed crystal after 20 minutes at the pulling speed of 3mm/h, slowly cooling to room temperature after necking, shouldering and equal-diameter growth stages, and taking out the crystal. Cutting and polishing the crystal to obtain 5 × 5 × 1mm³The wafer of (1). As shown in FIG. 5, the resistivity test gave β - (Ga)_0.93Al_0.07)₂O₃The resistivity of the crystal was 8.5X 10⁹Omega cm. Preparation of a catalyst based on beta- (Ga)_0.93Al_0.07)₂O₃The radiation detector of the crystal has the detection sensitivity of 174 mu C Gy to X-rays at the voltage of 200V^-1cm^-2。

Example 6:

growing beta- (Ga) by guided mode method_0.92Al_0.08)₂O₃And (4) crystals.

Ga is weighed according to the molar ratio of 0.92:0.08₂O₃Powder and Al₂O₃Grinding the powder for 60 minutes to uniformly mix the powder, pressing the uniformly mixed powder into cakes by using a hydraulic press, and sintering the raw materials in a muffle furnace at 1450 ℃ in air for 20 hours to prepare a polycrystalline material. Putting the polycrystal material into an iraurita crucible, covering the crucible cover, and putting the polycrystal material into the iraurita crucible<010>The directional seed crystal is fixed in the seed crystal rod clamp. Vacuumizing to 7Pa, and filling CO₂And (3) heating to 1.05MPa until the raw material is completely melted, descending the seed crystal to contact with the melt at the top of the die, pulling at a speed of 3mm/h after seeding and necking, performing isodiametric growth at a pulling speed of 5mm/h after the crystal is fully placed to the width of the die, slowly cooling to room temperature after the growth is finished, and taking out the crystal. Cutting and polishing the crystal to obtain 5 × 5 × 1mm³The wafer of (1). As shown in FIG. 5, the resistivity test gave β - (Ga)_0.92Al_0.08)₂O₃The resistivity of the crystal was 3.2X 10¹⁰Omega cm. Preparation of a catalyst based on beta- (Ga)_0.92Al_0.08)₂O₃The radiation detector of the crystal has the detection sensitivity of 215 mu C Gy to X-rays at the voltage of 200V^{- 1}cm^-2。

The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.