Nitride semiconductor blue laser element

Abstract

The nitride semiconductor blue laser element comprises a substrate, a lower limiting layer, a lower waveguide layer, an active layer, an upper waveguide layer and an upper limiting layer which are sequentially arranged from bottom to top, and a topological photon electronic composite flat band layer is arranged between the lower limiting layer and the lower waveguide layer. The topological photon electron composite flat band layer has a refractive index coefficient distribution characteristic and a forbidden band width distribution characteristic. According to the invention, an electron energy band and a photon energy band form high-dimensional line degeneracy in a momentum space, the interaction intensity of free electrons and photons is enhanced, the phase mismatch of the free electrons and the photons is overcome, the radiation intensity of the free electrons is excited, the free electron coupling light quantum efficiency is improved, and full energy-momentum matched flat band resonance is realized. Laser far-field radiation is enhanced, and laser mode gain and optical power are improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor optoelectronic devices, and in particular to a nitride semiconductor blue light laser element. Background Art

[0002] Lasers are widely used in laser display, laser TV, laser projector, communication, medical treatment, weapons, guidance, ranging, spectral analysis, cutting, precision welding, high-density optical storage and other fields. There are many types of lasers, and the classification methods are also diverse, mainly including solid, gas, liquid, semiconductor and dye types of lasers; compared with other types of lasers, all-solid-state semiconductor lasers have the advantages of small size, high efficiency, light weight, good stability, long life, simple and compact structure, and miniaturization.

[0003] There are big differences between lasers and nitride semiconductor light-emitting diodes:

[0004] 1) Laser is generated by stimulated radiation of carriers, the spectrum half-width is small, the brightness is very high, and the output power of a single laser can be in the W level, while nitride semiconductor light-emitting diodes are spontaneously radiated, and the output power of a single light-emitting diode is in the mW level;

[0005] 2) The current density of the laser reaches KA / cm2, 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;

[0006] 3) The spontaneous transition radiation of the light-emitting diode is incoherent light that transitions from a high energy level to a low energy level without any external influence, while the laser is stimulated transition radiation, and the energy of the induced photon should be equal to the difference in the energy level of the electron transition, producing the same coherent light as the photon and the induced photon;

[0007] 4) Different principles: When an external voltage is applied to a light-emitting diode, electron holes jump to a quantum well or a pn junction to generate radiative recombination light, while a laser can only emit when the lasing conditions are met. The carrier distribution in the active region must be reversed, and the stimulated radiation light oscillates back and forth in the resonant cavity. The propagation in the gain medium amplifies the light, and the threshold condition is met so that the gain is greater than the loss, and finally the laser is output.

[0008] Nitride semiconductor lasers have the following problems: high optical waveguide absorption loss, inherent carbon impurities in p-type semiconductors will compensate for acceptors and destroy p-type, etc., the p-type doping has a low ionization rate, and a large amount of unionized Mg acceptor impurities will cause internal optical losses to increase. In addition, the refractive index of the laser is dispersed, and the high-concentration carrier concentration fluctuations affect the refractive index of the active layer. The limitation factor decreases with increasing wavelength, resulting in a decrease in the mode gain of the laser. Summary of the invention

[0009] To solve one of the above technical problems, the present invention provides a nitride semiconductor blue laser element.

[0010] An embodiment of the present invention provides a nitride semiconductor blue laser element, comprising a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer and an upper confinement layer, which are sequentially arranged from bottom to top; a topological photon-electron composite flat band layer is arranged between the lower confinement layer and the lower waveguide layer; the topological photon-electron composite flat band layer comprises a first topological photon-electron composite flat band layer, a second topological photon-electron composite flat band layer and a third topological photon-electron composite flat band layer, which are sequentially arranged from bottom to top; the first topological photon-electron composite flat band layer, the second topological photon-electron composite flat band layer and the third topological photon-electron composite flat band layer all have a refractive index coefficient distribution characteristic and a bandgap width distribution characteristic;

[0011] The refractive index coefficient of the first topological photonic electronic composite flat band layer is distributed as a linear function;

[0012] The refractive index coefficient of the second topological photonic electron composite flat band layer is y1=A+B*e x1 sinx1 curve distribution;

[0013] The refractive index coefficient of the third topological photonic electron composite flat band layer is y2=C+D*sinx2 / x2 2 The third quadrant curve distribution;

[0014] The bandgap width of the first topological photon-electron composite flat band layer is distributed as a linear function;

[0015] The bandgap width of the second topological photon-electron composite flat band layer is y3=E+F*x1 2 +G*sinx1 curve distribution;

[0016] The bandgap width of the third topological photon-electron composite flat band layer is y4=x2e x2 Curve distribution;

[0017] Among them, x1 is the depth of the second topological photonic electron composite flat band layer towards the third topological photonic electron composite flat band layer, and x2 is the depth of the third topological photonic electron composite flat band layer towards the lower waveguide layer.

[0018] Preferably, the refractive index coefficient of the first topological photonic electron composite flat band layer is a, the refractive index coefficient of the second topological photonic electron composite flat band layer is b, and the refractive index coefficient of the third topological photonic electron composite flat band layer is c, wherein 1≤a≤b≤c≤5.

[0019] Preferably, the bandgap width of the first topological photonic electron composite flat band layer is d, the bandgap width of the second topological photonic electron composite flat band layer is e, and the bandgap width of the third topological photonic electron composite flat band layer is f, wherein 0.5eV≤f≤e≤d≤10eV.

[0020] Preferably, the first topological photonic electronic composite flat band layer, the second topological photonic electronic composite flat band layer and the third topological photonic electronic composite flat band layer also have lattice constant distribution characteristics;

[0021] The lattice constant of the first topological photonic-electronic composite flat band layer is distributed as a linear function;

[0022] The lattice constant of the second topological photon-electron composite flat band layer is y5=H+J*ln(x1+1)-K*e x1 Curve distribution;

[0023] The lattice constant of the third topological photonic electron composite flat band layer is distributed in the fourth quadrant curve of y6=x2 / lnx2;

[0024] The lattice constant of the first topological photonic electron composite flat band layer is g, the lattice constant of the second topological photonic electron composite flat band layer is h, and the lattice constant of the third topological photonic electron composite flat band layer is i, wherein 2 angstroms ≤ g ≤ h ≤ i ≤ 10 angstroms.

[0025] Preferably, the first topological photonic electron composite flat band layer, the second topological photonic electron composite flat band layer and the third topological photonic electron composite flat band layer also have Philips ionization degree distribution characteristics;

[0026] The Philips ionization degree of the first topological photon-electron composite flat band layer is distributed as a linear function;

[0027] The Philips ionization degree of the second topological photon-electron composite flat band layer is y7=L+M*x1 2 sinx1 first quadrant curve distribution;

[0028] The Philips ionization degree of the third topological photon-electron composite flat band layer is y8=N+P*e x2 / x2 third quadrant curve distribution;

[0029] The Philips ionization degree of the first topological photon-electron recombination flat band layer is j, the Philips ionization degree of the second topological photon-electron recombination flat band layer is k, and the Philips ionization degree of the third topological photon-electron recombination flat band layer is l, wherein 0.1≤j≤k≤l≤5.

[0030] Preferably, the first topological photonic electronic composite flat band layer, the second topological photonic electronic composite flat band layer and the third topological photonic electronic composite flat band layer also have an In / C element ratio distribution characteristic;

[0031] The In / C element ratio of the first topological photonic electronic composite flat band layer is distributed as a linear function;

[0032] The In / C element ratio of the second topological photonic electron composite flat band layer is y9=Q+R*x1 2 sinx1 first quadrant curve distribution;

[0033] The In / C element ratio of the third topological photonic electron composite flat band layer is y 10 =S+T*e x2 / x2 third quadrant curve distribution.

[0034] Preferably, the first topological photonic electronic composite flat band layer, the second topological photonic electronic composite flat band layer and the third topological photonic electronic composite flat band layer also have an In / H element ratio distribution characteristic;

[0035] The In / H element ratio of the first topological photonic electronic composite flat band layer is distributed as a linear function;

[0036] The In / H element ratio of the second topological photonic electron composite flat band layer is y 11 =U+V*ln(x1+1)-e x1 Curve distribution;

[0037] The In / H element ratio of the third topological photonic electron composite flat band layer is y 12 =O+W*+x2 / lnx2 fourth quadrant curve distribution.

[0038] Preferably, the first topological photonic electronic composite flat band layer, the second topological photonic electronic composite flat band layer and the third topological photonic electronic composite flat band layer also have an In / O element ratio distribution characteristic;

[0039] The In / O element ratio of the first topological photonic electronic composite flat band layer is distributed as a linear function;

[0040] The In / O element ratio of the second topological photonic electron composite flat band layer is y 13 =I+e x1 sinx1 curve distribution;

[0041] The In / O element ratio of the third topological photonic electron composite flat band layer is y 14 =Z+sinx2 / x2 2 The third quadrant curve distribution.

[0042] Preferably, the first topological photonic electronic composite flat band layer, the second topological photonic electronic composite flat band layer and the third topological photonic electronic composite flat band 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, BN, diamond, KMn6Bi5, KAg(CN)2, Pb2SbO7, Rb2CaH4, and Ca2NCl.

[0043] 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 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 angstroms to 100 angstroms, and 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, BN, and diamond, with a thickness of 10 angstroms to 150 angstroms.

[0044] Preferably, the lower limiting layer, the lower waveguide layer, the upper waveguide layer, and the upper limiting 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.

[0045] Preferably, the substrate comprises 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 Any one of a composite substrate, a magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2 and LiGaO2 composite substrate.

[0046] The beneficial effects of the present invention are as follows: the present invention provides a topological photon-electron composite flat band layer of a multilayer structure between the lower confinement layer and the lower waveguide layer of the nitride semiconductor blue laser element, and defines the refractive index coefficient distribution characteristics and the bandgap width distribution characteristics of each topological photon-electron composite flat band layer. The specific refractive index coefficient distribution and the bandgap width distribution of the topological photon-electron composite flat band layer form the flat band orbit characteristics, so that the electron energy band and the photon energy band form a high-dimensional line degeneracy in the momentum space, enhance the interaction intensity between free electrons and photons, overcome the phase mismatch between free electrons and photons, excite the radiation intensity of free electrons, improve the free electron coupling light quantum efficiency, realize the flat band resonance of full energy-momentum matching, enhance the laser far-field radiation, and improve the laser mode gain and optical power. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0048] Figure 1 A schematic diagram of the structure of a nitride semiconductor blue laser element according to an embodiment of the present invention;

[0049] Figure 2 This is a SIMS secondary ion mass spectrum of the nitride semiconductor blue laser element described in an embodiment of the present invention.

[0050] Reference numerals:

[0051] 100, substrate, 101, lower confinement layer, 102, lower waveguide layer, 103, active layer, 104, upper waveguide layer, 105, upper confinement layer, 106, topological photonic electronic composite flat band layer;

[0052] 106a, a first topological photonic electron composite flat band layer, 106b, a second topological photonic electron composite flat band layer, 106c, a third topological photonic electron composite flat band layer. DETAILED DESCRIPTION

[0053] In order to make the technical solutions and advantages in the embodiments of the present application more clearly understood, the exemplary embodiments of the present application are further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than an exhaustive list of all the embodiments. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0054] like Figure 1 and Figure 2 As shown, this embodiment provides a nitride semiconductor blue laser element, comprising 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 arranged in sequence from bottom to top. A topological photonic electron composite flat band layer 106 is also arranged in the nitride semiconductor blue laser element.

[0055] Specifically, in this embodiment, the nitride semiconductor blue laser element is provided with 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 from bottom to top. The topological photon-electron composite flat band layer 106 is arranged between the lower confinement layer 101 and the lower waveguide layer 102. The topological photon-electron composite flat band layer 106 is a multi-layer structure, specifically a three-layer structure, including a first topological photon-electron composite flat band layer 106a, a second topological photon-electron composite flat band layer 106b and a third topological photon-electron composite flat band layer 106c. Among them, the first topological photon-electron composite flat band layer 106a, the second topological photon-electron composite flat band layer 106b and the third topological photon-electron composite flat band layer 106c are arranged from bottom to top between the lower confinement layer 101 and the lower waveguide layer 102.

[0056] In this embodiment, the first topological photonic electron composite flat band layer 106a, the second topological photonic electron composite flat band layer 106b and the third topological photonic electron composite flat band layer 106c all have specific refractive index coefficient distribution characteristics and bandgap width distribution characteristics, which are specifically manifested as follows:

[0057] Refractive index distribution:

[0058] The refractive index coefficient of the first topological photonic electronic composite flat band layer 106a is distributed in a linear function;

[0059] The refractive index coefficient of the second topological photonic electron composite flat band layer 106b is y1=A+B*e x1 sinx1 curve distribution;

[0060] The refractive index coefficient of the third topological photonic electron composite flat band layer 106c is y2=C+D*sinx2 / x2 2 The third quadrant curve distribution;

[0061] Wherein, x1 is the depth from the second topological photonic electron composite flat band layer 106 b to the third topological photonic electron composite flat band layer 106 c , and x2 is the depth from the third topological photonic electron composite flat band layer 106 c to the lower waveguide layer 102 .

[0062] Bandgap width distribution:

[0063] The bandgap width of the first topological photonic electron composite flat band layer 106a is distributed in a linear function;

[0064] The bandgap width of the second topological photon-electron composite flat band layer 106b is y3=E+F*x1 2 +G*sinx1 curve distribution;

[0065] The bandgap width of the third topological photon-electron composite flat band layer 106c is y4=x2e x2 Curved distribution.

[0066] In this embodiment, a multi-layer topological photon-electron composite flat band layer 106 is arranged between the lower confinement layer 101 and the lower waveguide layer 102 of the nitride semiconductor blue laser element, and the refractive index coefficient distribution characteristics and the bandgap width distribution characteristics of each layer of the topological photon-electron composite flat band layer 106 are defined. The specific refractive index coefficient distribution and the bandgap width distribution of the topological photon-electron composite flat band layer 106 form flat band orbit characteristics, so that the electron energy band and the photon energy band form a high-dimensional line degeneracy in the momentum space, enhance the interaction intensity between free electrons and photons, overcome the phase mismatch between free electrons and photons, excite the radiation intensity of free electrons, improve the free electron coupling light quantum efficiency, achieve full energy-momentum matching flat band resonance, enhance laser far-field radiation, and improve laser mode gain and optical power.

[0067] In some optional embodiments, the refractive index coefficients in the first topological photonic electron composite flat band layer 106a, the second topological photonic electron composite flat band layer 106b, and the third topological photonic electron composite flat band layer 106c also have the following relationship:

[0068] The refractive index coefficient of the first topological photonic electron composite flat band layer 106a is a, the refractive index coefficient of the second topological photonic electron composite flat band layer 106b is b, and the refractive index coefficient of the third topological photonic electron composite flat band layer 106c is c, wherein 1≤a≤b≤c≤5.

[0069] In some optional embodiments, the bandgap widths in the first topological photonic electron composite flat band layer 106a, the second topological photonic electron composite flat band layer 106b, and the third topological photonic electron composite flat band layer 106c also have the following relationship:

[0070] The bandgap width of the first topological photonic electron composite flat band layer 106a is d, the bandgap width of the second topological photonic electron composite flat band layer 106b is e, and the bandgap width of the third topological photonic electron composite flat band layer 106c is f, wherein 0.5eV≤f≤e≤d≤10eV.

[0071] In some optional embodiments, the first topological photonic electronic composite flat band layer 106a, the second topological photonic electronic composite flat band layer 106b and the third topological photonic electronic composite flat band layer 106c also have lattice constant distribution characteristics, which are specifically manifested as follows:

[0072] The lattice constant of the first topological photonic electron composite flat band layer 106a is distributed in a linear function;

[0073] The lattice constant of the second topological photonic electron composite flat band layer 106b is y5=H+J*ln(x1+1)-K*e x1 Curve distribution;

[0074] The lattice constant of the third topological photonic electron composite flat band layer 106c is distributed in the fourth quadrant curve of y6=x2 / lnx2;

[0075] The lattice constants in the first topological photonic electron composite flat band layer 106a, the second topological photonic electron composite flat band layer 106b and the third topological photonic electron composite flat band layer 106c also have the following relationship:

[0076] The lattice constant of the first topological photonic electron composite flat band layer 106a is g, the lattice constant of the second topological photonic electron composite flat band layer 106b is h, and the lattice constant of the third topological photonic electron composite flat band layer 106c is i, wherein 2 angstroms ≤ g ≤ h ≤ i ≤ 10 angstroms.

[0077] In some optional embodiments, the first topological photonic electron composite flat band layer 106a, the second topological photonic electron composite flat band layer 106b and the third topological photonic electron composite flat band layer 106c also have Philips ionization degree distribution characteristics, which are specifically manifested as follows:

[0078] The Philips ionization degree of the first topological photon-electron composite flat band layer 106a is distributed as a linear function;

[0079] The Philips ionization degree of the second topological photon-electron composite flat band layer 106b is y7=L+M*x1 2 sinx1 first quadrant curve distribution;

[0080] The Philips ionization degree of the third topological photon-electron composite flat band layer 106c is y8=N+P*e x2 / x2 third quadrant curve distribution;

[0081] The Philips ionization degrees in the first topological photonic electron composite flat band layer 106a, the second topological photonic electron composite flat band layer 106b, and the third topological photonic electron composite flat band layer 106c also have the following relationship:

[0082] The Philips ionization degree of the first topological photonic electron recombination flat band layer 106a is j, the Philips ionization degree of the second topological photonic electron recombination flat band layer 106b is k, and the Philips ionization degree of the third topological photonic electron recombination flat band layer 106c is l, wherein 0.1≤j≤k≤l≤5.

[0083] The specific lattice constant distribution and Philips ionization degree distribution in the first topological photonic electron composite flat band layer 106a, the second topological photonic electron composite flat band layer 106b and the third topological photonic electron composite flat band layer 106c form a stable closed ring Dirac nodal line that is not easily destroyed, and produce a strong localized near field in the transverse periodic structure, reduce energy dispersion, induce reduction of refractive index dispersion, increase the confinement factor, enhance the mode gain, generate in-plane anisotropy and vibration anisotropy, reduce optical waveguide absorption loss, reduce internal optical loss, thereby enhancing the stimulated radiation of the laser element and improving the laser power and slope efficiency of the laser element.

[0084] In some optional embodiments, the first topological photonic electronic composite flat band layer 106a, the second topological photonic electronic composite flat band layer 106b and the third topological photonic electronic composite flat band layer 106c also have an In / C element ratio distribution characteristic, which is specifically manifested as follows:

[0085] The In / C element ratio of the first topological photonic electronic composite flat band layer 106a is distributed in a linear function;

[0086] The In / C element ratio of the second topological photonic electron composite flat band layer 106b is y9=Q+R*x1 2 sinx1 first quadrant curve distribution;

[0087] The In / C element ratio of the third topological photonic electron composite flat band layer 106c is y 10 =S+T*e x2 / x2 third quadrant curve distribution.

[0088] In some optional embodiments, the first topological photonic electronic composite flat band layer 106a, the second topological photonic electronic composite flat band layer 106b and the third topological photonic electronic composite flat band layer 106c also have an In / H element ratio distribution characteristic, which is specifically manifested as follows:

[0089] The In / H element ratio of the first topological photonic electronic composite flat band layer 106a is distributed as a linear function;

[0090] The In / H element ratio of the second topological photonic electron composite flat band layer 106b is y 11 =U+V*ln(x1+1)-e x1 Curve distribution;

[0091] The In / H element ratio of the third topological photonic electron composite flat band layer 106c is y 12 =O+W*+x2 / lnx2 fourth quadrant curve distribution.

[0092] In some optional embodiments, the first topological photonic electronic composite flat band layer 106a, the second topological photonic electronic composite flat band layer 106b and the third topological photonic electronic composite flat band layer 106c also have an In / O element ratio distribution characteristic, which is specifically manifested as follows:

[0093] The In / O element ratio of the first topological photonic electronic composite flat band layer 106a is distributed in a linear function;

[0094] The In / O element ratio of the second topological photonic electron composite flat band layer 106b is y 13 =I+e x1 sinx1 curve distribution;

[0095] The In / O element ratio of the third topological photonic electron composite flat band layer 106c is y 14 =Z+sinx2 / x2 2 The third quadrant curve distribution.

[0096] The specific element ratio distributions (In / C element ratio distribution, In / H element ratio distribution, In / O element ratio distribution) of the first topological photonic electron composite flat band layer 106a, the second topological photonic electron composite flat band layer 106b and the third topological photonic electron composite flat band layer 106c further form non-flat energy bands with quasi-planar energy band hybridization, enhance the interaction strength between free electrons and photons, improve the free electron coupling light quantum efficiency, reduce the refractive index dispersion of the laser, reduce the optical waveguide absorption loss, and reduce the internal optical loss, thereby enhancing the stimulated radiation of the laser element and improving the laser power and slope efficiency of the laser element.

[0097] In some optional embodiments, the first topological photonic electron composite flat band layer 106a, the second topological photonic electron composite flat band layer 106b and the third topological photonic electron composite flat band layer 106c 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, BN, diamond, KMn6Bi5, KAg(CN)2, Pb2SbO7, Rb2CaH4, and Ca2NCl.

[0098] In some optional embodiments, the active layer 103 is a periodic structure composed of a well layer and a barrier layer, and the number of periods is 3≥m≥1.

[0099] The well 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, and has a thickness of 10 to 100 angstroms.

[0100] 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, BN, and diamond, with a thickness of 10 to 150 angstroms.

[0101] In some optional embodiments, 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.

[0102] In some optional embodiments, 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 Any one of a composite substrate, a magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2 and LiGaO2 composite substrate.

[0103] The following table is a parameter comparison between a conventional semiconductor laser element and the nitride semiconductor blue laser element proposed in this embodiment, including slope efficiency, threshold current density, optical power, internal optical loss, and limiting factor to present the difference between the conventional semiconductor laser element and the nitride semiconductor blue laser element proposed in this embodiment:

[0104]

[0105] It can be seen that the nitride semiconductor blue laser element proposed in this embodiment has improved slope efficiency, optical power and limitation factor, reduced threshold current density and internal optical loss compared with traditional semiconductor laser elements, and has obvious advantages over traditional semiconductor laser elements.

[0106] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A nitride semiconductor blue laser element, comprising a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer and an upper confinement layer arranged in sequence from bottom to top, characterized in that: A topological photon-electron composite flat band layer is arranged between the lower confinement layer and the lower waveguide layer, and the topological photon-electron composite flat band layer comprises a first topological photon-electron composite flat band layer, a second topological photon-electron composite flat band layer and a third topological photon-electron composite flat band layer which are arranged in sequence from bottom to top, and the first topological photon-electron composite flat band layer, the second topological photon-electron composite flat band layer and the third topological photon-electron composite flat band layer all have a refractive index coefficient distribution characteristic and a bandgap width distribution characteristic; The refractive index coefficient of the first topological photonic electronic composite flat band layer is distributed as a linear function; The refractive index coefficient of the second topological photonic electron composite flat band layer is y1=A+B*e x1 sinx1 curve distribution; The refractive index coefficient of the third topological photonic electron composite flat band layer is y2=C+D*sinx2 / x2 2 The third quadrant curve distribution; The bandgap width of the first topological photon-electron composite flat band layer is distributed as a linear function; The bandgap width of the second topological photon-electron composite flat band layer is y3=E+F*x1 2 +G*sinx1 curve distribution; The bandgap width of the third topological photon-electron composite flat band layer is y4=x2e x2 Curve distribution; Among them, x1 is the depth of the second topological photonic electron composite flat band layer towards the third topological photonic electron composite flat band layer, and x2 is the depth of the third topological photonic electron composite flat band layer towards the lower waveguide layer.

2. The nitride semiconductor blue laser device according to claim 1, characterized in that: The refractive index coefficient of the first topological photonic electron composite flat band layer is a, the refractive index coefficient of the second topological photonic electron composite flat band layer is b, and the refractive index coefficient of the third topological photonic electron composite flat band layer is c, wherein 1≤a≤b≤c≤5.

3. The nitride semiconductor blue laser device according to claim 1, wherein: The bandgap width of the first topological photonic electron composite flat band layer is d, the bandgap width of the second topological photonic electron composite flat band layer is e, and the bandgap width of the third topological photonic electron composite flat band layer is f, wherein 0.5eV≤f≤e≤d≤10eV.

4. The nitride semiconductor blue laser device according to claim 1, wherein: The first topological photonic electron composite flat band layer, the second topological photonic electron composite flat band layer and the third topological photonic electron composite flat band layer also have lattice constant distribution characteristics; The lattice constant of the first topological photonic-electronic composite flat band layer is distributed as a linear function; The lattice constant of the second topological photon-electron composite flat band layer is y5=H+J*ln(x1+1)-K*e x1 Curve distribution; The lattice constant of the third topological photonic electron composite flat band layer is distributed in the fourth quadrant curve of y6=x2 / lnx2; The lattice constant of the first topological photonic electron composite flat band layer is g, the lattice constant of the second topological photonic electron composite flat band layer is h, and the lattice constant of the third topological photonic electron composite flat band layer is i, wherein 2 angstroms ≤ g ≤ h ≤ i ≤ 10 angstroms.

5. The nitride semiconductor blue laser device according to claim 1, wherein: The first topological photon-electron composite flat band layer, the second topological photon-electron composite flat band layer and the third topological photon-electron composite flat band layer also have Philips ionization degree distribution characteristics; The Philips ionization degree of the first topological photon-electron composite flat band layer is distributed as a linear function; The Philips ionization degree of the second topological photon-electron composite flat band layer is y7=L+M*x1 2 sinx1 first quadrant curve distribution; The Philips ionization degree of the third topological photon-electron composite flat band layer is y8=N+P*e x2 / x2 third quadrant curve distribution; The Philips ionization degree of the first topological photon-electron recombination flat band layer is j, the Philips ionization degree of the second topological photon-electron recombination flat band layer is k, and the Philips ionization degree of the third topological photon-electron recombination flat band layer is l, wherein 0.1≤j≤k≤l≤5.

6. The nitride semiconductor blue laser device according to claim 1, wherein: The first topological photonic electron composite flat band layer, the second topological photonic electron composite flat band layer and the third topological photonic electron composite flat band layer also have an In / C element ratio distribution characteristic; The In / C element ratio of the first topological photonic electronic composite flat band layer is distributed as a linear function; The In / C element ratio of the second topological photonic electron composite flat band layer is y9=Q+R*x1 2 sinx1 first quadrant curve distribution; The In / C element ratio of the third topological photonic electron composite flat band layer is y 10 =S+T*e x2 / x2 third quadrant curve distribution.

7. The nitride semiconductor blue laser device according to claim 1, wherein: The first topological photonic electron composite flat band layer, the second topological photonic electron composite flat band layer and the third topological photonic electron composite flat band layer also have an In / H element ratio distribution characteristic; The In / H element ratio of the first topological photonic electronic composite flat band layer is distributed as a linear function; The In / H element ratio of the second topological photonic electron composite flat band layer is y 11 =U+V*ln(x1+1)-e x1 Curve distribution; The In / H element ratio of the third topological photonic electron composite flat band layer is y 12 =O+W*+x2 / lnx2 fourth quadrant curve distribution.

8. The nitride semiconductor blue laser device according to claim 1, wherein: The first topological photonic electron composite flat band layer, the second topological photonic electron composite flat band layer and the third topological photonic electron composite flat band layer also have an In / O element ratio distribution characteristic; The In / O element ratio of the first topological photonic electronic composite flat band layer is distributed as a linear function; The In / O element ratio of the second topological photonic electron composite flat band layer is y 13 =I+e x1 sinx1 curve distribution; The In / O element ratio of the third topological photonic electron composite flat band layer is y 14 =Z+sinx2 / x2 2 The third quadrant curve distribution.

9. The nitride semiconductor blue laser device according to claim 1, wherein: The first topological photonic electron composite flat band layer, the second topological photonic electron composite flat band layer and the third topological photonic electron composite flat band 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, BN, diamond, KMn6Bi5, KAg(CN)2, Pb2SbO7, Rb2CaH4, and Ca2NCl.

10. The nitride semiconductor blue laser device according to claim 1, wherein: The active layer is a periodic structure composed of a well layer and a barrier layer, the number of periods is 3≥m≥1, the well 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, and the thickness is 1. The thickness is 10 angstroms to 100 angstroms, and 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, BN, and diamond, and the thickness is 10 angstroms to 150 angstroms; 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; 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 Any one of a composite substrate, a magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2 and LiGaO2 composite substrate.

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