A gallium nitride-based semiconductor laser element

Abstract

The present invention discloses a gallium nitride-based semiconductor laser element, comprising, from bottom to top, a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, and an upper confinement layer, with a quantum spin transport layer disposed between the active layer and the lower waveguide layer. The present invention enables the quantum spin transport layer to form a low-dimensional topological structure in which multiple topological surface states coexist, forming Dirac surface states. This structure enables long-distance spin transport under multiple topological protections, and synergistically regulates the topological energy bands and spin transport of the active and waveguide layers, thereby improving the spin-to-charge conversion efficiency, the uniformity of carrier injection into the active layer, the quantum recombination efficiency of the active layer, and the slope efficiency and optical power of the laser.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor optoelectronic devices, and in particular to a gallium nitride-based semiconductor laser element. Background Art

[0002] Lasers are widely used in laser displays, laser televisions, laser projectors, communications, medical treatment, weaponry, guidance, rangefinders, spectral analysis, cutting, precision welding, high-density optical storage, and other fields. There are many different types of lasers, classified in various ways, including solid-state, gas, liquid, semiconductor, and dye lasers. Compared with other types of lasers, all-solid-state semiconductor lasers offer advantages such as small size, high efficiency, light weight, excellent stability, long life, simple and compact structure, and miniaturization.

[0003] There are significant differences between lasers and nitride semiconductor light-emitting diodes: 1) Lasers are generated by stimulated emission of carriers, with a small spectral half-width and high brightness. The output power of a single laser can be in the W level, while nitride semiconductor light-emitting diodes emit spontaneous radiation, with the output power of a single light-emitting diode in the mW level; 2) The operating current density of the laser is up to KA / cm 2 , which is more than 2 orders of magnitude higher than that of nitride light-emitting diodes, resulting in stronger electron leakage, more serious Auger recombination, stronger polarization effect, more serious electron-hole mismatch, and more serious efficiency attenuation Droop effect; 3) The light-emitting diode spontaneously radiates incoherent light from high energy level to low energy level without external influence, while the laser is stimulated transition radiation. The energy of the induced photon should be equal to the difference in energy levels of the electron transition, generating completely coherent light of the photon and the induced photon; 4) The principle is different: the light-emitting diode is under the action of external voltage, and the electron hole transitions to the quantum well or pn junction to generate radiation recombination and emit light, while the laser needs to meet the lasing conditions before it can be lased. The carrier inversion distribution in the active area must be met. The stimulated radiation light oscillates back and forth in the resonant cavity, and the propagation in the gain medium amplifies the light. The threshold condition is met so that the gain is greater than the loss, and finally the laser is output.

[0004] Nitride semiconductor lasers have the following problems: the quantum well polarization electric field raises the hole injection barrier, holes overflow the active layer, and other issues. The uneven hole injection and low efficiency lead to severe electron-hole asymmetry mismatch in the quantum well, electron leakage and carrier delocalization, making hole transport in the quantum well more difficult, carrier injection uneven, and gain uneven. At the same time, the laser gain spectrum becomes wider and the peak gain decreases, resulting in an increase in the laser threshold current and a decrease in slope efficiency. The laser valence band step increases, making hole transport in the quantum well more difficult, carrier injection uneven, and gain uneven. Summary of the Invention

[0005] The present invention proposes a gallium nitride-based semiconductor laser element, which enables the quantum spin transport layer to form a low-dimensional topological structure in which multiple topological surface states coexist, forming Dirac surface states, constructing long-distance spin transport under multiple topological protection, and synergistically regulating the topological energy bands and spin transport of the active layer and waveguide layer, thereby improving the spin current-charge current conversion efficiency, improving the uniformity of carrier injection into the active layer, improving the quantum recombination efficiency of the active layer, and improving the slope efficiency and optical power of the laser.

[0006] The present invention provides a gallium nitride-based semiconductor laser element, which comprises, from bottom to top, a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, and an upper confinement layer. A quantum spin transport layer is provided between the active layer and the lower waveguide layer. The quantum spin transport layer is any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN, Co3O4, MnBi2Te4, VS2, VS, CsMnF3, and CsMnCl3.

[0007] Preferably, the electron mobility distribution of the quantum spin transport layer has the function y=A+B*sinx / e x Curve distribution; the electron mobility of the quantum spin transport layer ≤ the electron mobility of the lower waveguide layer ≤ the electron mobility of the active layer.

[0008] Preferably, the electron effective mass distribution of the quantum spin transport layer has the function y=C+D*x 2 sinx first quadrant curve distribution; the electron effective mass of the active layer ≤ the electron effective mass of the lower waveguide layer ≤ the electron effective mass of the quantum spin transport layer.

[0009] Preferably, the band gap distribution of the quantum spin transport layer has a function y=E+F*e x sinx curve distribution; the band gap width of the active layer ≤ the band gap width of the lower waveguide layer ≤ the band gap width of the quantum spin transport layer.

[0010] Preferably, the dielectric constant distribution of the quantum spin transport layer has the function y=G+H*x 2 +J*sinx curve distribution; the dielectric constant of the quantum spin transport layer ≤ the dielectric constant of the lower waveguide layer ≤ the dielectric constant of the active layer.

[0011] Preferably, the In element concentration distribution of the quantum spin transport layer has a function y=K+L*x 2 +M*sinx curve distribution; the In element concentration of the quantum spin transport layer ≤ the In element concentration of the lower waveguide layer ≤ the In element concentration of the active layer.

[0012] Preferably, the In / H element ratio distribution of the quantum spin transport layer has a function y=N+P*x 2 +Q*sinx curve distribution; the In / H element ratio of the quantum spin transport layer ≤ the In / H element ratio of the lower waveguide layer ≤ the In / H element ratio of the active layer;

[0013] The In / C element ratio distribution of the quantum spin transport layer has the function y=R+S*x 2 +T*sinx curve distribution; the In / C element ratio of the quantum spin transport layer ≤ the In / C element ratio of the lower waveguide layer ≤ the In / C element ratio of the active layer;

[0014] The In / O element ratio distribution of the quantum spin transport layer has a function y=U+V*x 2 +W*sinx curve distribution; the In / O element ratio of the quantum spin transport layer ≤ the In / O element ratio of the lower waveguide layer ≤ the In / O element ratio of the active layer.

[0015] Preferably, the electron mobility distribution, electron effective mass distribution, bandgap width distribution, and dielectric constant distribution of the quantum spin transport layer have the following relationship: C≤E≤G≤A; the In element concentration distribution, In / H element ratio distribution, In / C element ratio distribution, and In / O element ratio distribution of the quantum spin transport layer have the following relationship: N≤U≤R≤K.

[0016] Preferably, the active layer is a periodic structure composed of a well layer and a barrier layer, the number of periods is 3 ≥ m ≥ 1, and the well layer is any one of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN or any combination thereof, with a thickness of 10 to 120 angstroms, and the barrier layer being any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, and BN, with a thickness of 10 to 200 angstroms.

[0017] Preferably, the lower confinement layer, the lower waveguide layer, the upper waveguide layer, and the upper confinement layer are any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, and BN.

[0018] Preferably, the substrate includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite substrate, sapphire / AlN composite substrate, sapphire / SiN x , sapphire / SiO2 / SiN x Composite substrate, any one of magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2 and LiGaO2 composite substrates.

[0019] Compared with the prior art, the gallium nitride-based semiconductor laser element provided by the embodiment of the present invention has the following beneficial effects:

[0020] The quantum spin transport layer forms a low-dimensional topological structure with multiple topological surface states coexisting, forming Dirac surface states, constructing long-distance spin transport under multiple topological protection, and synergistically regulating the topological energy bands and spin transport of the active layer and waveguide layer, thereby improving the spin-charge flow conversion efficiency, improving the uniformity of carrier injection into the active layer, improving the quantum recombination efficiency of the active layer, and improving the slope efficiency and optical power of the laser;

[0021] The active layer and the waveguide layer form a huge spin momentum splitting, generate a spin triplet supercurrent, increase the carrier transport channel, enhance the injection of spin-polarized holes into the active layer, regulate the polarization electric field of the active layer, increase the electron and hole transport in the active layer, improve the overlap probability of the electron-hole wave function and the uniformity of the electron-hole distribution in the active layer, accelerate the stimulated radiation of the laser element, reduce the excitation threshold of the laser element, enhance the confinement factor, and improve the lasing power and slope efficiency of the laser element;

[0022] Further enhance the topological energy band and spin transport regulation of the active layer and waveguide layer, reduce the valence band order of the laser, enhance the hole transport in the active layer, accelerate the population inversion of the active layer, increase the peak gain, enhance the stimulated radiation of the laser, and reduce the excitation threshold of the laser element. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 1 is a schematic structural diagram of a gallium nitride-based semiconductor laser element according to an embodiment of the present invention;

[0024] Figure 2 This is a SIMS secondary ion mass spectrum of the structure of a gallium nitride-based semiconductor laser element according to an embodiment of the present invention;

[0025] Reference numerals: 100: substrate; 101: lower confinement layer; 102: lower waveguide layer; 103: active layer; 104: upper waveguide layer, 105: upper confinement layer, 106: quantum spin transport layer. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0027] In order to solve the above problems, a gallium nitride-based semiconductor laser element provided in an embodiment of the present application will be introduced and explained in detail through the following specific embodiments.

[0028] Reference Figure 1-2The present invention provides a gallium nitride-based semiconductor laser element, which comprises, from bottom to top, a substrate 100, a lower confinement layer 101, a lower waveguide layer 102, an active layer 103, an upper waveguide layer 104, and an upper confinement layer 105. A quantum spin transport layer 106 is provided between the active layer 103 and the lower waveguide layer 102. The quantum spin transport layer 106 is GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs , AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN, Co3O4, MnBi2Te4, VS2, VS, CsMnF3, CsMnCl3, any one or any combination.

[0029] The electron mobility distribution of the quantum spin transport layer 106 has the function y=A+B*sinx / e x curve distribution; the electron mobility of the quantum spin transport layer 106 ≤ the electron mobility of the lower waveguide layer 102 ≤ the electron mobility of the active layer 103 .

[0030] The electron effective mass distribution of the quantum spin transport layer 106 has the function y=C+D*x 2 sinx first quadrant curve distribution; the electron effective mass of the active layer 103 ≤ the electron effective mass of the lower waveguide layer 102 ≤ the electron effective mass of the quantum spin transport layer 106 .

[0031] The band gap distribution of the quantum spin transport layer 106 has the function y=E+F*e x sinx curve distribution; the band gap width of the active layer 103 ≤ the band gap width of the lower waveguide layer 102 ≤ the band gap width of the quantum spin transport layer 106.

[0032] The dielectric constant distribution of the quantum spin transport layer 106 has the function y=G+H*x 2 +J*sinx curve distribution; the dielectric constant of the quantum spin transport layer 106 ≤ the dielectric constant of the lower waveguide layer 102 ≤ the dielectric constant of the active layer 103 .

[0033] In summary, the quantum spin transport layer 106 forms a low-dimensional topological structure in which multiple topological surface states coexist, forming Dirac surface states, constructing long-distance spin transport under multiple topological protection, and synergistically regulating the topological energy bands and spin transport of the active layer 103 and the waveguide layer, thereby improving the spin current-charge current conversion efficiency, improving the uniformity of carrier injection into the active layer, improving the quantum recombination efficiency of the active layer 103, and improving the slope efficiency and optical power of the laser.

[0034] The In element concentration distribution of the quantum spin transport layer 106 has a function y=K+L*x 2 +M*sinx curve distribution; the In element concentration of the quantum spin transport layer 106 ≤ the In element concentration of the lower waveguide layer 102 ≤ the In element concentration of the active layer 103 .

[0035] The In / H element ratio distribution of the quantum spin transport layer 106 has a function y=N+P*x 2 +Q*sinx curve distribution; the In / H element ratio of the quantum spin transport layer 106 ≤ the In / H element ratio of the lower waveguide layer 102 ≤ the In / H element ratio of the active layer 103;

[0036] The In / C element ratio distribution of the quantum spin transport layer 106 has a function y=R+S*x 2 +T*sinx curve distribution; the In / C element ratio of the quantum spin transport layer 106 ≤ the In / C element ratio of the lower waveguide layer 102 ≤ the In / C element ratio of the active layer 103;

[0037] The In / O element ratio distribution of the quantum spin transport layer 106 has a function y=U+V*x 2 +W*sinx curve distribution; the In / O element ratio of the quantum spin transport layer 106 ≤ the In / O element ratio of the lower waveguide layer 102 ≤ the In / O element ratio of the active layer 103 .

[0038] In summary, a huge spin momentum splitting is formed between the active layer 103 and the lower waveguide layer 102, a spin triplet supercurrent is generated, the carrier transport channel is increased, the spin polarized hole injection into the active layer 103 is enhanced, the polarization electric field of the active layer 103 is regulated, the electron and hole transport in the active layer 103 is increased, the overlapping probability of the electron-hole wave function and the uniformity of the electron-hole distribution in the active layer 103 are improved, the stimulated radiation of the laser element is accelerated, the excitation threshold of the laser element is reduced, the confinement factor is enhanced, and the lasing power and slope efficiency of the laser element are improved.

[0039] The electron mobility distribution, electron effective mass distribution, bandgap width distribution, and dielectric constant distribution of the quantum spin transport layer 106 have the following relationship: C≤E≤G≤A; the In element concentration distribution, In / H element ratio distribution, In / C element ratio distribution, and In / O element ratio distribution of the quantum spin transport layer 106 have the following relationship: N≤U≤R≤K. This further enhances the topological energy band and spin transport control of the active layer 103 and the lower waveguide layer 102, reduces the valence band order of the laser, enhances hole transport in the active layer 103, accelerates population inversion in the active layer 103, increases peak gain, enhances stimulated emission of the laser, and reduces the excitation threshold of the laser element.

[0040] The following table specifically shows a comparison of data between the conventional laser and the laser of the present invention.

[0041] Blue laser project Traditional lasers Laser of the present invention Range of change Slope efficiency (W / A) 0.8 1.39 74％ <![CDATA[Threshold current density (kA / cm 2 )]]> 2.4 0.73 -70％ Optical power (W) 5.2 12.7 144％ Limiting Factor 1.40％ 6.13％ 338％

[0042] In the present invention, the active layer 103 is a periodic structure composed of a well layer and a barrier layer, the period number is 3≥m≥1, and the well layer is any one of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, and BN. The barrier layer is any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, and BN, with a thickness of 10 to 200 angstroms.

[0043] In the present invention, the lower confinement layer 101, the lower waveguide layer 102, the upper waveguide layer 104, and the upper confinement layer 105 are any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, and BN.

[0044] In the present invention, the substrate 100 includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite substrate, sapphire / AlN composite substrate, sapphire / SiN x , sapphire / SiO2 / SiN x Composite substrate, any one of magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2 and LiGaO2 composite substrates.

[0045] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A gallium nitride-based semiconductor laser element, comprising, from bottom to top, a substrate (100), a lower confinement layer (101), a lower waveguide layer (102), an active layer (103), an upper waveguide layer (104), and an upper confinement layer (105), characterized in that: A quantum spin transport layer (106) is provided between the active layer (103) and the lower waveguide layer (102); The electron mobility distribution of the quantum spin transport layer (106) has the function y=A+B*sinx / e x Curve distribution; the electron mobility of the quantum spin transport layer (106) ≤ the electron mobility of the lower waveguide layer (102) ≤ the electron mobility of the active layer (103); The electron effective mass distribution of the quantum spin transport layer (106) has the function y=C+D*x 2 sinx first quadrant curve distribution; the electron effective mass of the active layer (103) ≤ the electron effective mass of the lower waveguide layer (102) ≤ the electron effective mass of the quantum spin transport layer (106); The band gap width distribution of the quantum spin transport layer (106) has the function y=E+F*e x sinx curve distribution; the band gap width of the active layer (103) is ≤ the band gap width of the lower waveguide layer (102) ≤ the band gap width of the quantum spin transport layer (106); The dielectric constant distribution of the quantum spin transport layer (106) has the function y=G+H*x 2 +J*sinx curve distribution; the dielectric constant of the quantum spin transport layer (106) ≤ the dielectric constant of the lower waveguide layer (102) ≤ the dielectric constant of the active layer (103); The In element concentration distribution of the quantum spin transport layer (106) has a function y=K+L*x 2 +M*sinx curve distribution; the In element concentration of the quantum spin transport layer (106) ≤ the In element concentration of the lower waveguide layer (102) ≤ the In element concentration of the active layer (103); The In / H element ratio distribution of the quantum spin transport layer (106) has a function y=N+P*x 2 +Q*sinx curve distribution; the In / H element ratio of the quantum spin transport layer (106) is ≤ the In / H element ratio of the lower waveguide layer (102) ≤ the In / H element ratio of the active layer (103); The In / C element ratio distribution of the quantum spin transport layer (106) has a function y=R+S*x 2 +T*sinx curve distribution; the In / C element ratio of the quantum spin transport layer (106) is ≤ the In / C element ratio of the lower waveguide layer (102) ≤ the In / C element ratio of the active layer (103); The In / O element ratio distribution of the quantum spin transport layer (106) has a function y=U+V*x 2 +W*sinx curve distribution; the In / O element ratio of the quantum spin transport layer (106) is ≤ the In / O element ratio of the lower waveguide layer (102) ≤ the In / O element ratio of the active layer (103); The electron mobility distribution, electron effective mass distribution, band gap width distribution, and dielectric constant distribution of the quantum spin transport layer (106) have the following relationship: C≤E≤G≤A; the In element concentration distribution, In / H element ratio distribution, In / C element ratio distribution, and In / O element ratio distribution of the quantum spin transport layer (106) have the following relationship: N≤U≤R≤K.

2. The gallium nitride-based semiconductor laser device according to claim 1, characterized in that: The quantum spin transport layer (106) is any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN, Co3O4, MnBi2Te4, VS2, VS, CsMnF3, and CsMnCl3.

3. The gallium nitride-based semiconductor laser device according to claim 1, characterized in that: The active layer (103) is a periodic structure composed of a well layer and a barrier layer, the number of periods is 3≥m≥1, and the well layer is any one of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN or any combination thereof, with a thickness of 10 to 120 angstroms, and the barrier layer being any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, and BN, with a thickness of 10 to 200 angstroms.

4. The gallium nitride-based semiconductor laser device according to claim 1, characterized in that: The lower confinement layer (101), the lower waveguide layer (102), the upper waveguide layer (104), and the upper confinement layer (105) are any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, and BN.

5. The gallium nitride-based semiconductor laser device according to claim 1, characterized in that: The substrate (100) includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite substrate, sapphire / AlN composite substrate, sapphire / SiN x , sapphire / SiO2 / SiN x Composite substrate, any one of magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2 and LiGaO2 composite substrates.

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