A nitride semiconductor blue laser element

Abstract

The present invention proposes a nitride semiconductor blue laser element comprising, arranged 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 topological photonic-electronic composite flat band layer is disposed between the lower confinement layer and the lower waveguide layer. The topological photonic-electronic composite flat band layer has a refractive index coefficient distribution and a bandgap width distribution. This invention achieves high-dimensional linear degeneracy of the electron and photonic energy bands in momentum space, enhancing the interaction strength between free electrons and photons, overcoming the phase mismatch between free electrons and photons, stimulating the radiation intensity of free electrons, and improving the free electron coupled light quantum efficiency. This achieves full energy-momentum matching of flat band resonance, enhancing far-field laser radiation, and increasing both laser mode gain and optical power.

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 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:

[0004] 1) Laser is generated by stimulated radiation 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, 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. The energy of the induced photon should be equal to the difference in the energy level of the electron transition, and the photon and the induced photon are completely coherent light;

[0007] 4) Different principles: Light-emitting diodes generate radiative recombination light when electrons and holes jump to quantum wells or pn junctions under the action of external voltage, while lasers require that lasing conditions be met before lasing. The carrier inversion distribution in the active region must be met, 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 the p-type, 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 confinement 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, arranged sequentially from bottom to top; a topological photonic electron composite flat band layer is provided between the lower confinement layer and the lower waveguide layer; the topological photonic electron composite flat band layer comprises a first topological photonic electron composite flat band layer, a second topological photonic electron composite flat band layer, and a third topological photonic electron composite flat band layer, each of which has 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 photonic-electronic composite flat band layer is distributed as a linear function;

[0015] The band gap 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 from the second topological photonic electron composite flat band layer to the third topological photonic electron composite flat band layer, and x2 is the depth from the third topological photonic electron composite flat band layer to 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, where 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 photonic 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-electronic 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 in 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 in 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 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;

[0039] The In / O element ratio of the first topological photonic electronic composite flat band layer is distributed in 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 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.

[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 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.

[0045] 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.

[0046] The beneficial effects of the present invention are as follows: The present invention provides a multi-layer topological photonic electron composite flat band layer between the lower confinement layer and the lower waveguide layer of a nitride semiconductor blue laser element, and defines the refractive index coefficient distribution characteristics and bandgap width distribution characteristics of each topological photonic electron composite flat band layer. The specific refractive index coefficient distribution and bandgap width distribution of the topological photonic electron composite flat band layer form flat band orbital characteristics, causing the electron energy band and the photon energy band to form a high-dimensional linear degeneracy in momentum space, enhancing the interaction strength between free electrons and photons, overcoming the phase mismatch between free electrons and photons, stimulating the radiation intensity of free electrons, improving the free electron coupled light quantum efficiency, achieving full energy-momentum matching flat band resonance, enhancing laser far-field radiation, and improving 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 This is a schematic structural diagram 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 device according to 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-electronic recombination flat band layer, 106b, a second topological photonic-electronic recombination flat band layer, 106c, a third topological photonic-electronic recombination flat band layer. DETAILED DESCRIPTION

[0053] In order to make the technical solutions and advantages of the embodiments of the present application more clearly understood, the exemplary embodiments of the present application are further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, and are not an exhaustive list of all the embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other unless they conflict.

[0054] like Figure 1 and Figure 2 As shown, this embodiment provides a nitride semiconductor blue laser element, comprising, arranged 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 topological photonic-electronic composite flat-band layer 106 is also provided 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, sequentially from bottom to top. A topological photonic electron composite flat band layer 106 is provided between the lower confinement layer 101 and the lower waveguide layer 102. The topological photonic electron composite flat band layer 106 has a multilayer structure, specifically a three-layer structure, including a first topological photonic electron composite flat band layer 106a, a second topological photonic electron composite flat band layer 106b, and a third topological photonic electron composite flat band layer 106c. 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 sequentially provided, from bottom to top, between the lower confinement layer 101 and the lower waveguide layer 102.

[0056] In this embodiment, 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 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 band gap width of the second topological photon-electron composite flat band layer 106b is y3=E+F*x1 2 +G*sinx1 curve distribution;

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

[0066] In this embodiment, a multi-layer topological photonic electron composite flat band layer 106 is disposed between the lower confinement layer 101 and the lower waveguide layer 102 of the nitride semiconductor blue laser element. The refractive index coefficient distribution and bandgap width distribution characteristics of each topological photonic electron composite flat band layer 106 are defined. The specific refractive index coefficient distribution and bandgap width distribution of the topological photonic electron composite flat band layer 106 form flat band orbital characteristics, which cause the electron energy band and the photon energy band to form a high-dimensional linear degeneracy in momentum space. This enhances the interaction strength between free electrons and photons, overcomes the phase mismatch between free electrons and photons, excites the radiation intensity of free electrons, improves the free electron coupled light quantum efficiency, achieves full energy-momentum matching flat band resonance, enhances laser far-field radiation, and increases laser mode gain and optical power.

[0067] In some optional embodiments, the refractive index coefficients in 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 further 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, where 1≤a≤b≤c≤5.

[0069] In some optional embodiments, the bandgap widths 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 have the following relationship:

[0070] The bandgap width of the first topological photonic electron recombination flat band layer 106a is d, the bandgap width of the second topological photonic electron recombination flat band layer 106b is e, and the bandgap width of the third topological photonic electron recombination flat band layer 106c is f, where 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-electronic 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-electronic composite flat band layer 106c is distributed in the fourth quadrant curve of y6=x2 / lnx2;

[0075] The lattice constants 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 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, where 2 angstroms ≤ g ≤ h ≤ i ≤ 10 angstroms.

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

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

[0079] The Philips ionization degree of the second topological photon-electron recombination 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 recombination 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 recombination flat band layer 106 a , the second topological photonic electron recombination flat band layer 106 b , and the third topological photonic electron recombination flat band layer 106 c 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, where 0.1≤j≤k≤l≤5.

[0083] The specific lattice constant distribution and Philip 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, improve confinement factor, enhance 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, specifically manifested as:

[0085] The In / C element ratio of the first topological photonic electron 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, specifically manifested as:

[0089] The In / H element ratio of the first topological photonic electron composite flat band layer 106a is distributed in 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, specifically manifested as:

[0093] The In / O element ratio of the first topological photonic electron 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 distribution (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 forms a non-flat energy band with quasi-planar energy band hybridization, enhances the interaction strength between free electrons and photons, improves the free electron coupling light quantum efficiency, reduces the refractive index dispersion of the laser, reduces the optical waveguide absorption loss, and reduces 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, with a thickness of 10 angstroms 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 angstroms 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 Composite substrate, any one of magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2 and LiGaO2 composite substrates.

[0103] The following table compares the parameters of a conventional semiconductor laser device and the nitride semiconductor blue laser device proposed in this embodiment, including slope efficiency, threshold current density, optical power, internal optical loss, and limiting factor, showing the differences between the conventional semiconductor laser device and the nitride semiconductor blue laser device 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 may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is 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 order from bottom to top, characterized in that: A topological photonic electron composite flat band layer is provided between the lower confinement layer and the lower waveguide layer, wherein the topological photonic electron composite flat band layer comprises a first topological photonic electron composite flat band layer, a second topological photonic electron composite flat band layer and a third topological photonic electron composite flat band layer which are sequentially arranged from bottom to top, 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 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 photonic-electronic composite flat band layer is distributed as a linear function; The band gap 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 from the second topological photonic electron composite flat band layer to the third topological photonic electron composite flat band layer, and x2 is the depth from the third topological photonic electron composite flat band layer to the lower waveguide layer.

2. The nitride semiconductor blue laser device according to claim 1, wherein: 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 band gap width of the first topological photonic electron composite flat band layer is d, the band gap width of the second topological photonic electron composite flat band layer is e, and the band gap 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 photonic 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-electronic 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 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 a Philips ionization degree distribution characteristic; 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 in 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 in 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 in 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, and BN, and the thickness is 100-1000 nm. The thickness of the barrier layer 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 Composite substrate, any one of magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2 and LiGaO2 composite substrates.

Images