A gallium nitride-based laser with high electrical injection efficiency and a preparation method and device thereof

Abstract

The application relates to the technical field of semiconductor lasers, in particular to a gallium nitride-based laser with high electric injection efficiency and a preparation method and device thereof. The laser comprises a substrate, an n-type gallium nitride layer, an n-type light confinement layer, an n-type spin-polarized injection layer, an n-type optical waveguide layer, a multi-quantum well active layer, a p-type optical waveguide layer, a p-type spin-polarized injection layer, a p-type light confinement layer and a p-type gallium nitride layer which are sequentially stacked on the substrate; and an n-electrode and a p-electrode are respectively arranged on the n-type gallium nitride layer and the p-type gallium nitride layer. The n-type spin-polarized injection layer is arranged between the n-type light confinement layer and the n-type optical waveguide layer, and the p-type spin-polarized injection layer is arranged between the p-type optical waveguide layer and the p-type light confinement layer, thereby forming a symmetrical double spin-polarized injection layer structure, realizing directional transmission and spin recombination of spin-polarized carriers, improving the electric injection efficiency of the laser, effectively reducing the threshold current of the gallium nitride-based laser and improving the efficiency and stability of the gallium nitride-based laser.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor lasers, in particular to a gallium nitride-based laser with high electrical injection efficiency and a preparation method and device thereof. BACKGROUND

[0002] As an important component of the third-generation semiconductor optoelectronic devices, gallium nitride (GaN) -based lasers have wide application prospects in the fields of solid-state lighting, optical communication, laser processing, laser display, etc., which also promotes the increasing demand for high-performance and high-efficiency gallium nitride-based lasers. Electrical injection efficiency, as one of the core parameters determining the performance of the laser, still faces significant technical bottlenecks, affecting the further improvement of the energy efficiency, output power and service life of the device.

[0003] There are various methods to improve the electrical injection efficiency of gallium nitride-based lasers, such as improving material quality, optimizing device structure design, and improving doping process, etc. The material quality can be improved by means such as reducing defect density through superlattice buffer layer, but the traditional device structure based on quantum well active layer design has insufficient confinement ability for carriers, which is limited by problems such as carrier non-radiative recombination, Auger effect and electron overflow, making it difficult to balance carrier injection and recombination efficiency. The gradient refractive index structure constructed in the waveguide layer or the electron blocking layer structure optimized in the p-type layer can suppress electron overflow, but often at the expense of the injection ability of holes, resulting in a less obvious effect on reducing threshold current, limiting the application of the device in high-power and low-power consumption scenarios. SUMMARY

[0004] The present application aims to provide a gallium nitride-based laser with high electrical injection efficiency and a preparation method and device thereof, which can improve the electrical injection efficiency of the laser, effectively reduce the threshold current of the gallium nitride-based laser, and improve the efficiency and stability of the gallium nitride-based laser.

[0005] To achieve the above-mentioned purpose, the technical solution of the present application is a gallium nitride-based laser with high electrical injection efficiency, which comprises a substrate and an n-type gallium nitride layer, an n-type light confinement layer, an n-type spin polarization injection layer, an n-type optical waveguide layer, a multi-quantum well active layer, a p-type optical waveguide layer, a p-type spin polarization injection layer, a p-type light confinement layer, and a p-type gallium nitride layer which are sequentially stacked on the substrate; the n-type gallium nitride layer and the p-type gallium nitride layer are respectively provided with an n-electrode and a p-electrode.

[0006] As one of the embodiments, the n-type spin polarization injection layer is doped with spin-polarized n-type doping ions and first spin-polarized magnetic ions, and the p-type spin polarization injection layer is doped with spin-polarized p-type doping ions and second spin-polarized magnetic ions.

[0007] As one of the embodiments, the doping concentration of the spin-polarized n-type doping ion, the first spin-polarized magnetic ion, the spin-polarized p-type doping ion and the second spin-polarized magnetic ion is gradiently changed from the n-type gallium nitride layer to the p-type gallium nitride layer, and the gradient direction of the doping concentration of the spin-polarized n-type doping ion is opposite to the gradient direction of the doping concentration of the spin-polarized p-type doping ion, and the gradient direction of the doping concentration of the first spin-polarized magnetic ion is opposite to the gradient direction of the doping concentration of the second spin-polarized magnetic ion.

[0008] As one of the embodiments, the doping concentration of the spin-polarized n-type doping ion ranges from 5×10 17 cm -3 ~5×10 19 cm -3 , the doping concentration of the first spin-polarized magnetic ion ranges from 0.1~10at%, the doping concentration of the spin-polarized p-type doping ion ranges from 5×10 19 cm -3 ~5×10 21 cm -3 , and the doping concentration of the second spin-polarized magnetic ion ranges from 0.1~10at%.

[0009] As one of the embodiments, the doping concentration gradient of the spin-polarized n-type doping ion, the first spin-polarized magnetic ion, the spin-polarized p-type doping ion and the second spin-polarized magnetic ion is ≥10% / nm. The doping concentration gradient refers to the change rate of the concentration of the doping ion in the semiconductor material with the position, and the calculation formula of the doping concentration gradient in the n-type spin-polarized injection layer and the p-type spin-polarized injection layer is as follows:

[0010] D=(N2-N1) / (N1×(x2-x1))

[0011] Wherein, the doping concentration at the position x1 is N1, the doping concentration at the position x2 is N2, and N2>N1.

[0012] As one of the embodiments, the thickness of the n-type spin-polarized injection layer is 5~20nm, and the thickness of the p-type spin-polarized injection layer is 5~20nm.

[0013] The application also provides a preparation method of the gallium nitride-based laser as described in any one of the above embodiments, comprising the following steps:

[0014] S1, epitaxially growing an n-type gallium nitride layer and an n-type light confinement layer on a substrate in sequence;

[0015] S2, epitaxially growing an n-type spin-polarized injection layer on the n-type light confinement layer;

[0016] S3, growing an n-type optical waveguide layer, a multi-quantum well active layer and a p-type optical waveguide layer on the n-type spin-polarized injection layer in sequence;

[0017] S4, growing a p-type spin-polarized injection layer on the p-type optical waveguide layer;

[0018] S5, growing a p-type optical confinement layer and a p-type gallium nitride layer on the p-type spin-polarized injection layer in sequence;

[0019] S6, depositing an n-electrode and a p-electrode on surfaces of the n-type gallium nitride layer and the p-type gallium nitride layer.

[0020] As one of the embodiments, the n-type spin-polarized injection layer in step S2 and the p-type spin-polarized injection layer in step S4 are both formed by using a spin-polarized ion beam growth technology, generating spin-polarized doping ion beams by spin-polarized electron bombardment on gaseous doping atoms, and gradient doping into a gallium nitride layer.

[0021] The application also provides a device for preparing the gallium nitride-based laser as described in any one of the above, characterized in that: comprising a reaction cavity, a tray assembly, a spin-polarized ion beam generator one and a spin-polarized ion beam generator two; the spin-polarized ion beam generator one and the spin-polarized ion beam generator two are arranged at the top of the reaction cavity, for providing spin-polarized doping ion beams when the n-type spin-polarized injection layer and the p-type spin-polarized injection layer are grown; the tray assembly is arranged at the bottom in the reaction cavity, for placing a substrate to be processed; a reaction source inlet one and a reaction source inlet two are arranged on one side of the reaction cavity, for introducing gases required for epitaxial growth of each layer; an exhaust outlet is arranged on the other side of the reaction cavity, for discharging reaction residual gas.

[0022] As one of the embodiments, the spin-polarized ion beam generator one and the spin-polarized ion beam generator two have the same structure, both comprising a spin-polarized ionization cavity and a spin-polarized electron source for providing spin-polarized electrons, the spin-polarized electron source is connected with the spin-polarized ionization cavity through a polarized electron acceleration tube, the spin-polarized ionization cavity is connected with the reaction cavity through a polarized ion beam transmission channel, and the spin-polarized ionization cavity is provided with at least one gaseous atom inlet.

[0023] Compared with the prior art, the application has the following beneficial effects:

[0024] (1) The application realizes the directional transmission and spin recombination of spin-polarized carriers, improves the electric injection efficiency of the laser, effectively reduces the threshold current of the gallium nitride-based laser, and improves the efficiency and stability of the gallium nitride-based laser by setting the n-type spin-polarized injection layer between the n-type light confinement layer and the n-type light waveguide layer and setting the p-type spin-polarized injection layer between the p-type light waveguide layer and the p-type light confinement layer.

[0025] (2) The doping concentration gradient direction of the spin-polarized n-type doping ions is opposite to the doping concentration gradient direction of the spin-polarized p-type doping ions, the doping concentration gradient direction of the first spin-polarized magnetic ions is opposite to the doping concentration gradient direction of the second spin-polarized magnetic ions from the n-type gallium nitride layer to the p-type gallium nitride layer, a symmetrical double spin-polarized injection layer structure is formed, the spin ion injection concentration and depth are controlled to form a gradient doping interface, the Rashba effect of the gallium nitride material interface is utilized, the characteristics of the spin direction and momentum of the carriers induced by the spin-polarized injection layer are utilized to prolong the spin relaxation time, the spin matching of the electrons and holes is realized, and the recombination loss of the electrons and holes can be reduced.

[0026] (3) The high electric injection efficiency gallium nitride-based laser, the preparation method and the device are especially suitable for high-power and high-stability blue light and violet light lasers. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0028] Figure 1 A schematic diagram of the high electric injection efficiency gallium nitride-based laser provided by the embodiment of the present application is shown in the figure.

[0029] Figure 2 A flowchart of the preparation method of the gallium nitride-based laser provided by the embodiment of the present application is shown in the figure.

[0030] Figure 3 A structural schematic diagram of the device for the preparation method of the gallium nitride-based laser provided by the embodiment of the present application is shown in the figure.

[0031] In the figure: 101 - substrate, 102 - n-type gallium nitride layer, 103 - n-type optical confinement layer, 104 - n-type spin-polarized injection layer, 105 - n-type optical waveguide layer, 106 - multi-quantum well active layer, 107 - p-type optical waveguide layer, 108 - p-type spin-polarized injection layer, 109 - p-type optical confinement layer, 110 - p-type gallium nitride layer, 111 - n-electrode, 112 - p-electrode;

[0032] 201 - reaction cavity, 202 - substrate tray, 203 - support, 204 - heater, 205 - tail gas outlet, 206 - reaction source inlet one, 207 - reaction source inlet two, 301 - spin-polarized electron source one, 302 - polarized electron acceleration tube one, 303 - spin-polarized ionization cavity one, 304 - polarized ion beam transmission channel one, 305 - gaseous atom inlet one, 306 - gaseous atom inlet two, 401 - spin-polarized electron source two, 402 - polarized electron acceleration tube two, 403 - spin-polarized ionization cavity two, 404 - polarized ion beam transmission channel two, 405 - gaseous atom inlet three, 406 - gaseous atom inlet four. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0034] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0035] The terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features; in the description of the present application, unless otherwise stated, the meaning of "multiple" is two or more.

[0036] Embodiment one: as Figure 1As shown, the embodiment provides a gallium nitride-based laser with high electrical injection efficiency, which comprises a substrate 101, and an n-type gallium nitride layer 102, an n-type light confinement layer 103, an n-type spin-polarized injection layer 104, an n-type optical waveguide layer 105, a multi-quantum well active layer 106, a p-type optical waveguide layer 107, a p-type spin-polarized injection layer 108, a p-type light confinement layer 109, and a p-type gallium nitride layer 110, which are sequentially stacked on the substrate 101; and an n-electrode 111 and a p-electrode 112 are respectively arranged on the n-type gallium nitride layer 102 and the p-type gallium nitride layer 110.

[0037] The embodiment realizes directional transmission and spin recombination of spin-polarized carriers by arranging the n-type spin-polarized injection layer 104 between the n-type light confinement layer 103 and the n-type optical waveguide layer 105, and arranging the p-type spin-polarized injection layer 108 between the p-type optical waveguide layer 107 and the p-type light confinement layer 109, thereby improving the electrical injection efficiency of the laser, effectively reducing the threshold current of the gallium nitride-based laser, and improving the efficiency and stability of the gallium nitride-based laser.

[0038] Further, the n-type spin-polarized injection layer 104 is doped with spin-polarized n-type doping ions and first spin-polarized magnetic ions, and the p-type spin-polarized injection layer 108 is doped with spin-polarized p-type doping ions and second spin-polarized magnetic ions. In the embodiment, the n-type spin-polarized injection layer 104 is doped with a semiconductor material of first spin-polarized magnetic ions, in which the local magnetic moment formed by the first spin-polarized magnetic ions and the transport electrons in the n-type semiconductor produce exchange interaction, specifically, when a plurality of electrons enter the n-type polarization injection layer 104, the local magnetic moment regulates the spin state of the electrons through exchange coupling mechanism, so as to make the spin direction of the injected electrons tend to be highly consistent, thereby realizing efficient spin polarization of the electrons; similarly, the p-type spin-polarized injection layer 108 is doped with a semiconductor material of second spin-polarized magnetic ions, which produces an equivalent spin polarization effect in the hole injection process through the local magnetic field characteristics of the material, specifically, when the holes enter the p-type spin-polarized injection layer 108, the spin state of the holes is polarized by the second spin-polarized magnetic ions in the material, forming hole carriers with highly consistent spin direction; when the spin-polarized electrons and the spin-polarized holes are injected into the multi-quantum well active layer 106, the quantum states of the spin-polarized electrons and the spin-polarized holes are more matched due to the spin-polarized state, thereby increasing the recombination probability, so that the spin-polarized electrons and the spin-polarized holes are more likely to occur radiative recombination in the multi-quantum well structure of the active layer, thereby generating more photons and improving the internal quantum efficiency.

[0039] Optimally, the doping concentrations of the spin-polarized n-type doping ions, the first spin-polarized magnetic ions, the spin-polarized p-type doping ions and the second spin-polarized magnetic ions are gradiently changed in the direction from the n-type gallium nitride layer to the p-type gallium nitride layer, the gradient direction of the doping concentration of the spin-polarized n-type doping ions is opposite to that of the spin-polarized p-type doping ions, and the gradient direction of the doping concentration of the first spin-polarized magnetic ions is opposite to that of the second spin-polarized magnetic ions. In the n-type spin-polarized injection layer 104 of the embodiment, the gradient direction of the doping concentration of the spin-polarized n-type doping ions is the same as that of the first spin-polarized magnetic ions, the gradient direction of the doping concentration of the spin-polarized p-type doping ions is the same as that of the second spin-polarized magnetic ions, the gradient direction of the doping concentration of the spin-polarized n-type doping ions is opposite to that of the spin-polarized p-type doping ions, and the gradient direction of the doping concentration of the first spin-polarized magnetic ions is opposite to that of the second spin-polarized magnetic ions, thus forming a symmetric double spin-polarized injection layer structure, which can realize efficient recombination of electrons and holes. The principle is as follows: the same gradient of the n-type spin-polarized injection layer constructs a directional enhanced exchange field in the semiconductor matrix, which gradually increases the spin polarization degree of the injected electrons along the migration direction; the same gradient of the p-type spin-polarized injection layer realizes equivalent spin polarization enhancement of the holes through interatomic synergistic effect, the opposite gradient directions on both sides induce a symmetric built-in electric field at the interface of the multi-quantum well active layer, forming a transport potential well coupled by the carrier concentration gradient, which promotes the electrons and holes to converge to the center region of the active layer, significantly increasing the overlap probability of the electron-hole wave functions. Meanwhile, the polar crystal structure and the strong built-in electric field characteristics of the gallium nitride material are utilized to excite a significant Rashba effect at the gradient doping interface. The piezoelectric polarization of the wurtzite structure of the gallium nitride material and the high-mobility two-dimensional electron gas (2DEG) at the heterojunction interface (such as AlGaN / GaN) together generate an internal electric field of the order of MV / cm, which makes the spin direction and momentum state of the carriers form a locked relationship through spin-orbit coupling, effectively prolonging the spin relaxation time. By adjusting the spin ion injection concentration and depth, the gradient doping interface is formed. The spin direction of the electrons and the equivalent spin direction of the holes injected by the symmetric gradient structure are oriented and matched through the interface Rashba effect, the spin direction of the carriers is related to the momentum through the spin-polarized injection layer, the spin relaxation time is prolonged, the spin matching of the electrons and holes is realized, and the spin state-conserved radiative recombination in the multi-quantum well active layer is realized, avoiding the non-radiative recombination loss caused by the spin orientation mismatch.

[0040] In some embodiments, the doping concentration of the spin-polarized n-type dopant ions and the doping concentration of the first spin-polarized magnetic ions in the n-type spin-polarized injection layer 104 increase in a gradient from the n-type gallium nitride layer to the p-type gallium nitride layer; the doping concentration of the spin-polarized p-type dopant ions and the doping concentration of the second spin-polarized magnetic ions in the p-type spin-polarized injection layer 108 decrease in a gradient. The concentration gradient of the spin-polarized n-type dopant ions and the first spin-polarized magnetic ions in the n-type spin-polarized injection layer 104 can build an exchange field from weak to strong, so that the degree of spin polarization of the electrons increases during the migration to the multi-quantum well active layer, and the high-concentration doping region is close to the multi-quantum well active layer, providing stronger driving force for electron injection; the concentration gradient of the spin-polarized p-type dopant ions and the second spin-polarized magnetic ions in the p-type spin-polarized injection layer 108 can effectively reduce the potential barrier for hole injection into the active layer, making it easier for holes to diffuse into the multi-quantum well active layer, and the low-concentration region is close to the multi-quantum well active layer, reducing the scattering of impurities on the movement of holes. The concentration gradient on both sides can form an asymmetric built-in electric field on both sides of the multi-quantum well active layer, guiding electrons and holes to quickly converge to the center of the multi-quantum well active layer, improving the probability of wave function overlap, and thus enhancing the recombination efficiency of electrons and holes. In addition, the concentration difference between the high-concentration end of the n-type spin-polarized injection layer 104 and the low-concentration end of the p-type spin-polarized injection layer 108, combined with the Rashba effect of gallium nitride material, can further strengthen the spin-momentum locking relationship of carriers, prolong the spin relaxation time, and reduce the spin-related recombination loss.

[0041] In other embodiments, the doping concentration of the spin-polarized n-type dopant ions and the doping concentration of the first spin-polarized magnetic ions in the n-type spin-polarized injection layer 104 decrease in a gradient from the n-type gallium nitride layer to the p-type gallium nitride layer; the doping concentration of the spin-polarized p-type dopant ions and the doping concentration of the second spin-polarized magnetic ions in the p-type spin-polarized injection layer 108 increase in a gradient. The use of this concentration gradient distribution can form a reverse built-in electric field on both sides of the active layer, promoting the movement of electrons and holes to the center of the multi-quantum well active layer at a higher diffusion rate, and increasing the opportunity for carrier collision recombination.

[0042] In the embodiment, the spin-polarized n-type doping ions are any one of spin-polarized silicon ions, spin-polarized selenium ions, spin-polarized germanium ions, spin-polarized oxygen ions, and spin-polarized sulfur ions; the spin-polarized p-type doping ions are any one of spin-polarized magnesium ions, spin-polarized beryllium ions, and spin-polarized carbon ions; the first spin-polarized magnetic ions and the second spin-polarized magnetic ions are both spin-polarized transition metal magnetic ions, and specifically at least one of spin-polarized manganese ions, spin-polarized iron ions, and spin-polarized chromium ions can be used, and the first spin-polarized magnetic ions and the second spin-polarized magnetic ions can be the same spin-polarized magnetic ions or different spin-polarized magnetic ions.

[0043] The n-type spin-polarized injection layer 104 in the embodiment is gradiently doped with spin-polarized n-type doping ions and first spin-polarized magnetic ions by using a spin-polarized ion beam growth technology, and the p-type spin-polarized injection layer 108 is also gradiently doped with spin-polarized p-type doping ions and second spin-polarized magnetic ions by using the spin-polarized ion beam growth technology; the spin-polarized ion beam growth technology is doping by generating a spin-polarized doping ion beam through spin-polarized electron bombardment of gaseous doping atoms, wherein the spin-polarized electrons can be constant energy injection or intermittent pulse injection, and the gaseous doping atoms are gaseous n-type doping atoms, gaseous p-type doping atoms, and gaseous magnetic atoms, which respectively form spin-polarized n-type doping ions, spin-polarized p-type doping ions, and spin-polarized magnetic ions.

[0044] Further, the doping concentration of the spin-polarized n-type doping ions ranges from 5×10 17 cm -3 ~5×10 19 cm -3 , the doping concentration of the first spin-polarized magnetic ions ranges from 0.1 at% to 10 at%, the doping concentration of the spin-polarized p-type doping ions ranges from 5×10 19 cm -3 ~5×10 21 cm -3 , and the doping concentration of the second spin-polarized magnetic ions ranges from 0.1 at% to 10 at%.

[0045] Further, the doping concentration gradient of the spin-polarized n-type doping ion, the first spin-polarized magnetic ion, the spin-polarized p-type doping ion and the second spin-polarized magnetic ion is all ≥10% / nm. The numerical value of the doping concentration gradient affects the migration driving force of the carriers (electrons, holes) in the spin-polarized injection layer. The moderate numerical value of the concentration gradient of the spin-polarized doping ion and the spin-polarized magnetic ion can form a matching built-in electric field. The high gradient makes the exchange interaction between the local magnetic moment of the magnetic ion and the electron rapidly increase, which can improve the electron spin polarization degree in a short distance. When the doping concentration gradient of the spin-polarized n-type doping ion, the first spin-polarized magnetic ion, the spin-polarized p-type doping ion and the second spin-polarized magnetic ion is all ≥10% / nm, a strong enough built-in electric field can be formed in the injection layer to effectively drive the carrier migration and strengthen the spin polarization effect, thereby ensuring that the electrons and holes achieve efficient spin matching recombination in the multi-quantum well active layer.

[0046] The doping concentration gradient refers to the change rate of the concentration of the doping ion in the material with the change of the position. The calculation formula of the doping concentration gradient of the doping ion in the n-type spin-polarized injection layer 104 and the p-type spin-polarized injection layer 108 is:

[0047] D=(N2-N1) / (N1×(x2-x1))

[0048] Wherein, the doping concentration at the position x1 is N1, the doping concentration at the position x2 is N2, and N2>N1.

[0049] Further, the thickness of the n-type spin-polarized injection layer 104 is 5-20 nm, and the thickness of the p-type spin-polarized injection layer 108 is 5-20 nm.

[0050] Taking the n-type spin-polarized injection layer 104 as an example, the n-type doping ion concentration in the n-type spin-polarized injection layer 104 changes from N1=1×10 18 cm -3 to N2=5×10 18 cm -3 , the thickness of the n-type spin-polarized injection layer is 10 nm, that is, x2-x1=10 nm, and the doping concentration gradient is calculated as:

[0051] D=(5×10 18 -1×10 18 ) / (1×10 18 ×10nm)=4 / (1×10nm)=40% / nm.

[0052] In the embodiment, the substrate 101 can adopt a gallium nitride substrate 101, a sapphire substrate 101, a silicon carbide substrate 101 or a silicon substrate 101.

[0053] Further, the n-type gallium nitride layer 102 has a thickness of 1 μm to 3 μm, and a doping concentration of n-type dopant of 1×10 18 cm -3 to 2×10 19 cm -3 .

[0054] Further, the n-type light confinement layer 103 is made of n-type aluminum gallium nitride material, has a thickness of 0.5 μm to 1.5 μm, and a doping concentration of n-type dopant of 1×10 18 cm -3 to 2×10 19 cm -3 , and an aluminum component content of 15% to 30%. The n-type light confinement layer 103 can limit the expansion of the light field in the vertical direction, reduce the light field distribution range, and ensure that the light energy is concentrated in the multi-quantum well active layer 106 of the laser.

[0055] Further, the n-type light waveguide layer 105 is made of n-type aluminum gallium nitride material, has a thickness of 0.3 μm to 0.8 μm, and a doping concentration of n-type dopant of 1×10 18 cm -3 to 2×10 19 cm -3 . The n-type light waveguide layer 105 and the n-type light confinement layer 103 work together to compress the light field in the active layer, reduce the loss, and improve the light gain.

[0056] Further, the multi-quantum well active layer 106 is formed by alternately stacking indium gallium nitride well layers and gallium nitride barrier layers, and has a period number of 5 to 10 layers, wherein one indium gallium nitride well layer and one gallium nitride barrier layer form a period; the indium gallium nitride well layer has a thickness of 2 nm to 5 nm and an indium component content of 15% to 30%; and the gallium nitride barrier layer has a thickness of 3 nm to 10 nm.

[0057] Further, the p-type light waveguide layer 107 has a thickness of 0.3 μm to 0.8 μm, and a doping concentration of p-type dopant of 1×10 19 cm -3 to 2×10 21 cm -3 .

[0058] Further, the p-type light confinement layer 109 is made of p-type aluminum gallium nitride material, has a thickness of 0.5 μm to 1.5 μm, and an aluminum component content of 20% to 40%.

[0059] Further, the p-type gallium nitride layer 110 has a thickness of 0.2 μm to 1 μm, and a doping concentration of p-type dopant of 1×10 19 cm -3 to 2×10 21 cm-3 .

[0060] Further, the n-electrode 111 is a multi-layer film of titanium, aluminum, nickel, and gold, and the p-electrode 112 is a multi-layer film of nickel and gold.

[0061] In this embodiment, the n-type dopant is any one of silicon, selenium, germanium, oxygen, sulfur, etc., and the p-type dopant is any one of magnesium, beryllium, carbon, etc.

[0062] Embodiment Two: The embodiment provides a preparation method of the gallium nitride-based laser provided in Embodiment One, comprising the following steps:

[0063] S1. Epitaxially growing an n-type gallium nitride layer 102 and an n-type light confinement layer 103 on a substrate 101 in sequence;

[0064] S2. Epitaxially growing an n-type spin-polarized injection layer 104 on the n-type light confinement layer 103;

[0065] S3. Epitaxially growing an n-type optical waveguide layer 105, a multi-quantum well active layer 106, and a p-type optical waveguide layer 107 on the n-type spin-polarized injection layer 104 in sequence;

[0066] S4. Epitaxially growing a p-type spin-polarized injection layer 108 on the p-type optical waveguide layer 107;

[0067] S5. Epitaxially growing a p-type light confinement layer 109 and a p-type gallium nitride layer 110 on the p-type spin-polarized injection layer 108 in sequence;

[0068] S6. Depositing an n-electrode 111 and a p-electrode 112 on the surface of the n-type gallium nitride layer 102 and the p-type gallium nitride layer 110.

[0069] Further, the n-type spin-polarized injection layer 104 in step S2 and the p-type spin-polarized injection layer 108 in step S4 are both formed by spin-polarized ion beam growth technology, in which spin-polarized doping ions are generated by spin-polarized electrons bombarding gaseous doping atoms, and are gradient-doped into the gallium nitride layer. In this embodiment, the spin-polarized ion beam growth technology can realize atomic-level precision material growth, and can accurately control the injection concentration and depth of the spin-polarized ions, thereby forming a gradient-doped interface.

[0070] Specifically, in step S2, the method for epitaxially growing the n-type spin-polarized injection layer 104 on the n-type light confinement layer 103 is as follows: a gallium nitride layer is epitaxially grown on the n-type light confinement layer 103, and in the process of growing the gallium nitride layer, spin-polarized ion beam growth technology is adopted to generate spin-polarized n-type doping ions and first spin-polarized magnetic ions by spin-polarized electrons bombarding gaseous n-type doping atoms and gaseous magnetic atoms, respectively, and to gradient-dope the gallium nitride layer.

[0071] In this embodiment, after the n-type spin-polarized injection layer 104 is grown, the next step of growth can be directly performed, or in-situ annealing for no more than two minutes can be performed at the interface, and then the next step of growth is performed.

[0072] Specifically, in step S4, the method for epitaxially growing the p-type spin-polarized injection layer 108 on the p-type optical waveguide layer 107 is as follows: a gallium nitride layer is epitaxially grown on the p-type optical waveguide layer 107, and in the process of growing the gallium nitride layer, spin-polarized ion beam growth technology is used to generate spin-polarized p-type doping ions and second spin-polarized magnetic ions by respectively bombarding gaseous p-type doping atoms and gaseous magnetic atoms with spin-polarized electrons, and the gallium nitride layer is gradiently doped.

[0073] In this embodiment, after the p-type spin-polarized injection layer 108 is grown, the next step of growth can be directly performed, or in-situ annealing for no more than two minutes can be performed at the interface, and then the next step of growth is performed.

[0074] In this embodiment, the spin-polarized ion beam growth technology is used to dope spin-polarized n-type doping ions and first spin-polarized magnetic ions in the n-type spin-polarized injection layer 104 and to dope spin-polarized p-type doping ions and second spin-polarized magnetic ions in the p-type spin-polarized injection layer 108, so that electrons and holes are injected into the active layer in a spin-polarized manner, non-radiative recombination of the electrons and the holes is reduced, the internal quantum efficiency of the laser is effectively improved, the laser can achieve population inversion at a lower current injection, the threshold current is reduced, and the overall efficiency is improved; in addition, it is also beneficial to further optimize the active layer and the optical waveguide structure, so that the laser can stably work at a higher injection current, and the output power of the device is improved.

[0075] Embodiment three: the embodiment provides a device for preparing the gallium nitride-based laser in embodiment one, characterized in that: comprising a reaction cavity 201, a tray assembly, a spin-polarized ion beam generator one and a spin-polarized ion beam generator two, the spin-polarized ion beam generator one and the spin-polarized ion beam generator two are arranged at the top of the reaction cavity 201, for providing a spin-polarized doping ion beam when the n-type spin-polarized injection layer 104 and the p-type spin-polarized injection layer 108 are grown; the tray assembly is arranged at the bottom of the reaction cavity 201, for placing the substrate to be processed 101; one side of the reaction cavity 201 is provided with a reaction source inlet one 206 and a reaction source inlet two 207, for introducing the gas required for epitaxial growth of each layer; the other side of the reaction cavity 201 is provided with a tail gas outlet 205, for discharging the reaction residual gas. The embodiment places the substrate to be processed 101 through the tray assembly, introduces the gas required for epitaxial growth of each layer into the reaction cavity 201 through the reaction source inlet one 206 and the reaction source inlet two 207, so as to realize the growth of each epitaxial structure layer on the substrate 101, and through the accurate control of the flow, proportion and introduction time of the reaction source inlet, the accurate regulation of the material composition and thickness of each layer can be realized; the unreacted reactants, by-products and the like are discharged from the tail gas outlet 205 to the outside of the reaction cavity 201 in time; and when the n-type spin-polarized injection layer 104 is grown, the spin-polarized n-type doping ions and the spin-polarized magnetic ions are respectively generated by the spin-polarized ion beam generator one and the spin-polarized ion beam generator two and injected into the n-type spin-polarized injection layer 104, and when the p-type spin-polarized injection layer 108 is grown, the spin-polarized p-type doping ions and the spin-polarized magnetic ions are respectively generated by the spin-polarized ion beam generator one and the spin-polarized ion beam generator two and injected into the p-type spin-polarized injection layer 108.

[0076] Compared with the traditional process which needs to complete epitaxial growth and ion implantation in separate reaction cavities in turn, the embodiment integrates epitaxial growth and spin-polarized ion implantation in the same reaction cavity 201, which has the following advantages: first, the transfer step of the sample between different cavities can be eliminated, the process flow is greatly shortened, and the preparation efficiency of the gallium nitride-based laser is improved; second, the sample is prevented from contacting the external environment during the transfer process, the risk of surface contamination caused by environmental factors is reduced, and the material crystal quality and device performance are effectively guaranteed; third, through the accurate control of the temperature, gas pressure and ion beam flow parameters in the reaction cavity 201, the process of epitaxial layer growth and spin-polarized ion implantation is optimized, and the atomic level interface matching of the spin-polarized injection layer and the epitaxial layer is ensured, which provides reliable technical support for realizing high-performance devices.

[0077] In the embodiment, the tray assembly includes a substrate tray 202, a support 203, and a heater 204, the substrate tray 202 is arranged on the support 203, the support 203 is arranged at the bottom of the reaction cavity 201, and the support 203 can rotate to rotate with the substrate tray 202, promote the uniform distribution of the gas on the surface of the substrate 101, and improve the growth uniformity of the epitaxial layer; the heater 204 is arranged below the substrate tray 202 to make the substrate 101 reach a temperature suitable for epitaxial growth.

[0078] In the embodiment, the spin-polarized ion beam generator one and the spin-polarized ion beam generator two have the same structure, and both include a spin-polarized ionization cavity and a spin-polarized electron source for providing spin-polarized electrons, the spin-polarized electron source is connected with the spin-polarized ionization cavity through a polarized electron acceleration tube, the spin-polarized ionization cavity is connected with the reaction cavity 201 through a polarized ion beam transmission channel, and the spin-polarized ionization cavity is provided with at least one gaseous atom inlet. The spin-polarized electrons obtain sufficient energy through the polarized electron acceleration tube and are injected into the growth surface.

[0079] Specifically, the spin-polarized ion beam generator one includes a spin-polarized electron source one 301, a polarized electron acceleration tube one 302, a spin-polarized ionization cavity one 303, and a polarized ion beam transmission channel one 304; the spin-polarized electron source one 301 is connected with the spin-polarized ionization cavity one 303 through the polarized electron acceleration tube one 302, and is used for providing spin-polarized electrons into the spin-polarized ionization cavity one 303; the spin-polarized ionization cavity one 303 is connected with the reaction cavity 201 through the polarized ion beam transmission channel one 304, and is used for transmitting the generated spin-polarized ions into the reaction cavity 201 for doping; the spin-polarized ionization cavity one 303 is further provided with a gaseous atom inlet one 305 and a gaseous atom inlet two 306, and is used for providing atoms to be spin-polarized. In the embodiment, the gaseous n-type doping atoms or the gaseous p-type doping atoms are provided into the spin-polarized ionization cavity one 303 through the gaseous atom inlet one 305 or the gaseous atom inlet two 306, the spin-polarized electrons are provided into the spin-polarized ionization cavity one 303 through the polarized electron acceleration tube one 302, the spin-polarized n-type doping ions or the spin-polarized p-type doping ions can be formed under the action of the spin-polarized electrons, and reach the growth surface through the polarized ion beam transmission channel one 304, so as to realize the gradient doping of the spin-polarized n-type doping ions in the n-type spin-polarized injection layer 104 or the gradient doping of the spin-polarized p-type doping ions in the p-type spin-polarized injection layer 108.

[0080] The spin-polarized ion beam generator two comprises a spin-polarized electron source two 401, a polarized electron acceleration tube two 402, a spin-polarized ionization cavity two 403, and a polarized ion beam transmission channel two 404; the spin-polarized electron source two 401 is connected with the spin-polarized ionization cavity two 403 through the polarized electron acceleration tube two 402, and is used to provide spin-polarized electrons to the spin-polarized ionization cavity two 403; the spin-polarized ionization cavity two 403 is connected with the reaction cavity 201 through the polarized ion beam transmission channel two 404, and is used to transmit the generated spin-polarized ions to the reaction cavity 201 for doping; the spin-polarized ionization cavity two 403 is further provided with a gaseous atom inlet three 405 and a gaseous atom inlet four 406, and is used to provide atoms to be spin-polarized. In the embodiment, the first gaseous doping magnetic atom or the second gaseous doping magnetic atom is provided to the spin-polarized ionization cavity two 403 through the gaseous atom inlet three 405 or the gaseous atom inlet four 406, the spin-polarized electrons are provided to the spin-polarized ionization cavity two 403 through the polarized electron acceleration tube two 402, the first spin-polarized magnetic ion or the second spin-polarized magnetic ion can be formed under the action of the spin-polarized electrons, and reaches the growth surface through the polarized ion beam transmission channel two 404, so that the gradient doping of the first spin-polarized magnetic ion in the n-type spin-polarized injection layer 104 or the gradient doping of the second spin-polarized magnetic ion in the p-type spin-polarized injection layer 108 is realized.

[0081] Embodiment four: the preparation method of embodiment two is described in detail through a specific embodiment in combination with the device provided in embodiment three.

[0082] A preparation method of a gallium nitride-based laser with high electrical injection efficiency, comprising the following steps:

[0083] 1) Put the substrate 101 in the substrate tray 202 in the reaction cavity 201, pass the trimethyl gallium vapor into the reaction cavity 201 through the reaction source inlet one 206, pass the mixed gas of ammonia and silane into the reaction cavity 201 through the reaction source inlet two 207, the growth temperature is 1050°C, the reaction cavity pressure is 200mbar, and an n-type gallium nitride layer 102 with a thickness of 2μm and a silicon doping concentration of 3×10 18 cm -3 is epitaxially grown on the gallium nitride substrate 101, as the basis of the subsequent structure;

[0084] 2) pass the mixture of trimethyl gallium vapor and trimethyl aluminum vapor into the reaction cavity 201 through the reaction source inlet one 206, pass the mixed gas of ammonia and silane into the reaction cavity 201 through the reaction source inlet two 207, and epitaxially grow an n-type light confinement layer 103 with a thickness of 0.8μm and a silicon doping concentration of 2×10 18 cm -3, the aluminum component content is 20%, the layer is used for limiting the expansion of the light field in the vertical direction, reducing the light field distribution range, and ensuring that the light energy is concentrated on the multi-quantum well active layer 106 of the laser;

[0085] 3) pass the trimethyl gallium vapor through the reaction source inlet one 206 into the reaction cavity 201, pass the mixed gas of ammonia and silane through the reaction source inlet two 207 into the reaction cavity 201, reduce the pressure in the reaction cavity to 20 mbar, and epitaxially grow the n-type gallium nitride layer 102 on the n-type light confinement layer 103; in this process, the spin-polarized electrons generated in the spin-polarized electron source one 301 are transported to the spin-polarized ionization cavity one 303 through the polarized electron acceleration tube one 302, the spin-polarized electrons are injected in an intermittent pulse mode, the pulse injection duty cycle is 2:1, the gaseous doped silicon atoms enter the spin-polarized ionization cavity one 303 through the gaseous atom inlet one 305 and form spin-polarized silicon ions under the action of the spin-polarized electrons, and reach the growth surface through the polarized ion beam transmission channel one 304; the spin-polarized electrons generated in the spin-polarized electron source two 401 are transported to the spin-polarized ionization cavity two 403 through the polarized electron acceleration tube two 402, the spin-polarized electrons are injected in an intermittent pulse mode, the pulse injection duty cycle is 2:1, the gaseous doped manganese atoms enter the spin-polarized ionization cavity two 403 through the gaseous atom inlet three 405 and form spin-polarized manganese ions under the action of the spin-polarized electrons, and reach the growth surface through the polarized ion beam transmission channel two 404; the spin-polarized silicon ions and the spin-polarized manganese ions are synchronously injected into the n-type gallium nitride layer 102 in a gradient doping mode, forming an n-type spin-polarized injection layer 104, and the reaction residual gas is discharged from the reaction cavity 201 through the tail gas outlet 205; the doping concentration gradient of the n-type spin-polarized injection layer 104 is 90% / nm; the thickness of the n-type spin-polarized injection layer 104 is 10 nm, the doping concentration of the spin-polarized silicon ions is 5×10 18 cm -3 , gradually linearly increases to 5×10 19 cm -3 , forms a built-in polarization electric field by gradient doping, reduces the carrier transport barrier, and the doping concentration of the spin-polarized manganese ions is 0.2 at%, gradually linearly increases to 2 at%;

[0086] 4) pass the trimethyl gallium vapor through the reaction source inlet one 206 into the reaction cavity 201, pass the mixed gas of ammonia and silane through the reaction source inlet two 207 into the reaction cavity 201, and epitaxially grow the n-type light waveguide layer 105 on the n-type spin-polarized injection layer 104; the thickness of the n-type light waveguide layer 105 is 0.4 μm, and the silicon doping concentration is 2×10 18 cm -3The n-type optical waveguide layer 105 works together with the n-type optical confinement layer 103 to compress the optical field in the active layer, reduce the loss and increase the optical gain.

[0087] 5) Trimethylgallium vapor is introduced into the reaction cavity 201 through the reaction source inlet one 206, and the mixed gas of ammonia and silane is introduced into the reaction cavity 201 through the reaction source inlet two 207, the growth temperature is 750°C, and a multi-quantum well active layer 106 is grown on the n-type optical waveguide layer 105; the multi-quantum well active layer 106 is a periodic structure formed by alternately stacking indium gallium nitride well layers and gallium nitride barrier layers, the number of periods is 6 layers, the thickness of the indium gallium nitride well layer is 2 nm, the indium content is 20%, and the thickness of the gallium nitride barrier layer is 8 nm;

[0088] 6) The mixed gas of trimethylgallium vapor and dimethylmagnesium vapor is introduced into the reaction cavity 201 through the reaction source inlet one 206, and ammonia is introduced into the reaction cavity 201 through the reaction source inlet two 207, the growth temperature is 950°C, and a p-type optical waveguide layer 107 is epitaxially grown on the multi-quantum well active layer 106; the thickness of the p-type optical waveguide layer 107 is 0.5 μm, the magnesium doping concentration is 1×10 20 cm -3 ;

[0089] 7) the mixed vapors of trimethyl gallium and dimethyl magnesium are introduced into the reaction cavity 201 through the reaction source inlet one 206, ammonia is introduced into the reaction cavity 201 through the reaction source inlet two 207, the pressure in the reaction cavity is reduced to 20 mbar, and the p-type gallium nitride layer 110 is epitaxially grown on the p-type optical waveguide layer 107; in this process, the spin-polarized electrons generated in the spin-polarized electron source one 301 are transported to the spin-polarized ionization cavity one 303 through the polarized electron acceleration tube one 302, the spin-polarized electrons are injected in intermittent pulses, the pulse injection duty ratio is 2:1, the gaseous doped magnesium atoms enter the spin-polarized ionization cavity one 303 through the gaseous atom inlet one 305 and form spin-polarized magnesium ions under the action of the spin-polarized electrons, and reach the growth surface through the polarized ion beam transmission channel one 304; the spin-polarized electrons generated in the spin-polarized electron source two 401 are transported to the spin-polarized ionization cavity two 403 through the polarized electron acceleration tube two 402, the spin-polarized electrons are injected in intermittent pulses, the pulse injection duty ratio is 2:1, the gaseous doped chromium atoms enter the spin-polarized ionization cavity two 403 through the gaseous atom inlet three 405 and form spin-polarized chromium ions under the action of the spin-polarized electrons, and reach the growth surface through the polarized ion beam transmission channel two 404; the spin-polarized magnesium ions and the spin-polarized chromium ions are synchronously injected into the p-type gallium nitride layer 110 in a gradient doping manner, forming a p-type spin-polarized injection layer 108, and the reaction residual gas is discharged from the reaction cavity 201 through the tail gas outlet 205; the doping concentration gradient of the p-type spin-polarized injection layer 108 is 90% / nm, and the doping concentration gradient of the n-type spin-polarized injection layer 104 is opposite to that of the p-type spin-polarized injection layer 108 in the growth direction, and the p-type spin-polarized injection layer 108 and the n-type spin-polarized injection layer 104 form a symmetrical structure; the thickness of the p-type spin-polarized injection layer 108 is 10 nm, the doping concentration of the spin-polarized magnesium ions gradually linearly decreases from 5×10 20 cm -3 to 5×10 19 cm -3 , and the doping concentration of the spin-polarized chromium ions gradually linearly decreases from 2 at% to 0.2 at%;

[0090] 8) the mixed vapors of trimethyl gallium, dimethyl magnesium and trimethyl aluminum are introduced into the reaction cavity 201 through the reaction source inlet one 206, ammonia is introduced into the reaction cavity 201 through the reaction source inlet two 207, the pressure in the reaction cavity is 200 mbar, and the p-type optical confinement layer 109 is epitaxially grown on the p-type spin-polarized injection layer 108; the thickness of the p-type optical confinement layer 109 is 0.5 μm, and the aluminum component content is 20%;

[0091] 9) The mixed gas of trimethyl gallium vapor and dimethyl magnesium vapor is introduced into the reaction cavity 201 through the reaction source inlet 206, and ammonia is introduced into the reaction cavity 201 through the reaction source inlet 2 207, so as to epitaxially grow the p-type gallium nitride layer 110 on the p-type light confinement layer 109; the thickness of the p-type gallium nitride layer 110 is 0.3 μm, and the magnesium doping concentration is 2×10 20 cm -3 ;

[0092] 10) The n electrode 111 and the p electrode 112 are respectively deposited on the surfaces of the n-type gallium nitride layer 102 and the p-type gallium nitride layer 110 through photolithography and electron beam evaporation processes, so as to form a complete electric injection structure; the n electrode 111 is a three-layer film of titanium, nickel and gold, and the p electrode 112 is a double-layer film of nickel and gold.

[0093] The above only describes the preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A gallium nitride-based laser with high electrical injection efficiency, characterized in that: The system includes a substrate and, sequentially stacked on the substrate, an n-type gallium nitride layer, an n-type optical confinement layer, an n-type spin-polarized injection layer, an n-type optical waveguide layer, a multiple quantum well active layer, a p-type optical waveguide layer, a p-type spin-polarized injection layer, a p-type optical confinement layer, and a p-type gallium nitride layer. An n-electrode and a p-electrode are respectively disposed on the n-type gallium nitride layer and the p-type gallium nitride layer. The n-type spin-polarized injection layer is doped with a spin-polarized n-type dopant ion and a first spin-polarized magnetic ion, and the p-type spin-polarized injection layer is doped with a spin-polarized p-type dopant ion and a second spin-polarized magnetic ion. Spin-polarized magnetic ions; From the n-type gallium nitride layer to the p-type gallium nitride layer, the doping concentrations of the spin-polarized n-type dopant ion, the first spin-polarized magnetic ion, the spin-polarized p-type dopant ion, and the second spin-polarized magnetic ion all exhibit gradient changes, and the doping concentration gradient direction of the spin-polarized n-type dopant ion is opposite to that of the spin-polarized p-type dopant ion, and the doping concentration gradient direction of the first spin-polarized magnetic ion is opposite to that of the second spin-polarized magnetic ion.

2. The gallium nitride-based laser as described in claim 1, characterized in that: The doping concentration range of the spin-polarized n-type doped ions is 5 × 10⁻⁶. 17 cm -3 ~5×10 19 cm -3 The doping concentration of the first spin-polarized magnetic ion ranges from 0.1 to 10 at%; the doping concentration of the spin-polarized p-type dopant ion ranges from 5 × 10⁻⁶. 19 cm -3 ~5×10 21 cm -3 The doping concentration of the second spin-polarized magnetic ion ranges from 0.1 to 10 at.

3. The gallium nitride-based laser as described in claim 2, characterized in that: The doping concentration gradients of the spin-polarized n-type doped ion, the first spin-polarized magnetic ion, the spin-polarized p-type doped ion, and the second spin-polarized magnetic ion are all ≥10% / nm.

4. The gallium nitride-based laser as described in claim 1, characterized in that: The thickness of the n-type spin-polarized injection layer is 5~20nm, and the thickness of the p-type spin-polarized injection layer is 5~20nm.

5. A method for fabricating a gallium nitride-based laser according to any one of claims 1-4, characterized in that, Includes the following steps: S1. An n-type gallium nitride layer and an n-type light confinement layer are epitaxially grown sequentially on the substrate; S2. An n-type spin polarization injection layer is epitaxially grown on the n-type light confinement layer; S3. An n-type optical waveguide layer, a multi-quantum-well active layer, and a p-type optical waveguide layer are epitaxially grown sequentially on the n-type spin-polarized injection layer. S4. Epitaxially grow a p-type spin polarization injection layer on the p-type optical waveguide layer; S5. A p-type light confinement layer and a p-type gallium nitride layer are epitaxially grown sequentially on the p-type spin polarization injection layer; S6. Deposit n-electrode and p-electrode on the surfaces of the n-type gallium nitride layer and the p-type gallium nitride layer.

6. The preparation method according to claim 5, characterized in that: The n-type spin-polarized implanted layer in step S2 and the p-type spin-polarized implanted layer in step S4 are both formed by using spin-polarized ion beam growth technology. Spin-polarized doped ion beams are generated by bombarding gaseous dopant atoms with spin-polarized electrons and then gradient-doped into the gallium nitride layer.

7. An apparatus for fabricating a gallium nitride-based laser according to any one of claims 1-4, characterized in that: The device includes a reaction chamber, a tray assembly, a first spin-polarized ion beam generator, and a second spin-polarized ion beam generator. The first and second spin-polarized ion beam generators are located at the top of the reaction chamber and are used to provide spin-polarized doped ion beams during the growth of the n-type and p-type spin-polarized implanted layers. The tray assembly is located at the bottom of the reaction chamber and is used to hold the substrate to be processed. One side of the reaction chamber has a first reaction source inlet and a second reaction source inlet for introducing the gases required for each layer of epitaxial growth. The other side of the reaction chamber has a tail gas outlet for discharging residual reaction gases.

8. The apparatus as claimed in claim 7, characterized in that: The first and second spin-polarized ion beam generators have the same structure, both including a spin-polarized ionization cavity and a spin-polarized electron source for providing spin-polarized electrons. The spin-polarized electron source is connected to the spin-polarized ionization cavity through a polarized electron accelerating tube. The spin-polarized ionization cavity is connected to the reaction chamber through a polarized ion beam transmission channel. The spin-polarized ionization cavity is provided with at least one gaseous atom inlet.

Images