Semiconductor laser with exciton polaron topology layer

Abstract

The invention discloses a semiconductor laser with an exciton polaron topology layer, which sequentially comprises a substrate, a lower limiting layer, a lower waveguide layer, an active layer, an upper waveguide layer and an upper limiting layer from bottom to top, and is characterized in that the semiconductor laser is provided with the exciton polaron topology layer; the exciton polaron topology layer comprises a first exciton polaron topology layer, a second exciton polaron topology layer and a third exciton polaron topology layer, the first exciton polaron topology layer is located between the lower limiting layer and the substrate, the second exciton polaron topology layer is located in the lower limiting layer, and the third exciton polaron topology layer is located in the lower limiting layer. And the third exciton polaron topology layer is located between the lower limiting layer and the lower waveguide layer. According to the invention, the exciton polaron is used as a population inversion medium, the stability of exciton polaron quasi-particles is enhanced, the laser oscillation of the laser is enhanced, the threshold current of energy level population inversion of the laser is reduced, and the capture effect of a depletion region, a deep energy level trap and an insulating interface layer are improved.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor optoelectronic devices, and in particular to a semiconductor laser with an exciton-polariton topological layer. 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 significant 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 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;

[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 the active layer or pn junction to produce 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:

[0009] The lattice mismatch and large strain of the active layer induce a strong piezoelectric polarization effect, resulting in a strong QCSE quantum confined Stark effect. The step difference of the laser valence band increases, which inhibits hole injection, makes it more difficult for holes to transport in the quantum well, and causes uneven carrier injection and gain, which limits the improvement of the laser's electro-lasing gain. According to laser theory, after the laser emits stable laser saturation, the quasi-Fermi levels of holes and electrons are pinned, and the injected carriers are completely converted into photon output, the optical gain reaches saturation, the junction voltage also reaches saturation, and the carrier concentration in the cavity does not change with the current.

[0010] The symmetry breaking corresponding to the phase transition of the laser far from the equilibrium state causes discontinuity or mutation at the threshold of the laser, such as conductance jump, capacitance drop, junction voltage jump, series resistance drop, ideal factor jump, etc. This discontinuity phenomenon is mainly affected by the capture effect of the depletion region, surface conditions, edge effects, deep energy level traps, insulating interface layers and series resistance. Summary of the invention

[0011] The present invention proposes a semiconductor laser with an exciton-polariton topological layer. The exciton-polariton topological layer uses exciton-polaritons as a medium for particle number inversion, enhances the stability of exciton-polariton quasiparticles, enhances the laser oscillation of the laser, and reduces the threshold current for particle number inversion of the laser energy level. At the same time, the exciton-polaritons of the exciton-polariton topological layer have a faster relaxation rate, which improves the capture effect of the depletion region, deep energy level traps and insulating interface layer.

[0012] The present invention provides a semiconductor laser with an exciton polariton topological layer, 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, wherein the semiconductor laser has an exciton polariton topological layer; the exciton polariton topological layer comprises a first exciton polariton topological layer, a second exciton polariton topological layer, and a third exciton polariton topological layer, wherein the first exciton polariton topological layer is located between the lower confinement layer and the substrate, the second exciton polariton topological layer is located inside the lower confinement layer, and the third exciton polariton topological layer is located between the lower confinement layer and the lower waveguide layer;

[0013] The Al / O element ratio distribution of the first exciton polariton topological layer has an approximate function y=sinx / x 2 The third quadrant curve distribution; the Si / H element ratio distribution of the first exciton polariton topological layer has an approximate function y=ax 2 Curve distribution (a<0); The C / O element ratio distribution of the first exciton polariton topological layer has an approximate function y=(b x -1) / (b x +1)(0<b<1);

[0014] The In / O element ratio distribution of the second exciton polariton topological layer has an approximate function y=cx 2 distribution (c<0) curve distribution; the Si / O element ratio distribution of the second exciton polariton topological layer has an approximate function y=dx 2 distribution (d<0) curve distribution; the C / O element ratio distribution of the second exciton polariton topological layer has an approximate function y=x 2 / e x Curve distribution;

[0015] The Al / H element ratio distribution of the third exciton polariton topological layer has an approximate function y=lnx / x curve distribution; the Si / H element ratio of the third exciton polariton topological layer has an approximate function y=x 2 / e x Curve distribution; the C / O element ratio of the third exciton-polariton topological layer has a curve distribution that approximates a linear function.

[0016] Preferably, the well layer of the active layer is any one or any combination of InGaN, InN, AlInN, and GaN, with a thickness of 10 to 80 angstroms; the barrier layer of the active layer is any one or any combination of GaN, AlGaN, AlInGaN, AlN, and AlInN, with a thickness of 10 to 120 angstroms; the active layer is a periodic structure consisting of a well layer and a barrier layer, and the number of periods is 3≥m≥1.

[0017] Preferably, the thickness of the first exciton-polariton topological layer is m: 20≤m≤80000 angstroms; the thickness of the second exciton-polariton topological layer is n: 50≤n≤90000 angstroms; and the thickness of the third exciton-polariton topological layer is l: 10≤l≤70000 angstroms.

[0018] Preferably, the thicknesses of the first exciton-polariton topological layer, the second exciton-polariton topological layer, and the third exciton-polariton topological layer have the following relationship: l≤m≤n.

[0019] Preferably, the lower waveguide layer is InGaN with a thickness of 10 to 8000 angstroms; the upper waveguide layer is InGaN with a thickness of 10 to 8000 angstroms; the upper and lower limiting layers are any one or any combination of AlInGaN, AlInN, AlGaN, InGaN, GaN, AlInN, AlN, and InN, with a thickness of 10 to 9000 angstroms.

[0020] Preferably, the substrate comprises sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, sapphire / SiO 2 Composite substrate, Ga2 O 3 , diamond, sapphire / Al N composite substrate, sapphire / SiN x , Sapphire / SiO 2 / SiN x Composite substrate, magnesium aluminum spinel MgAl 2 O 4 、MgO、ZnO、ZrB 2 、LiAlO 2 and LiGaO 2 Any type of composite substrate.

[0021] Compared with the prior art, the semiconductor laser with an exciton-polariton topological layer provided by the embodiment of the present invention has the following beneficial effects: the exciton-polariton topological layer uses exciton-polariton as a medium for particle number inversion, enhances the stability of exciton-polariton quasiparticles, enhances the laser oscillation of the laser, and reduces the threshold current of the laser energy level particle number inversion. At the same time, the exciton-polariton of the exciton-polariton topological layer has a faster relaxation rate, improves the capture effect of the depletion region, the deep energy level trap and the insulating interface layer, and at the same time, the exciton-polariton of the exciton-polariton topological layer has a strong metallic property, suppresses the electron scattering on the surface and the interface, and forms a repeating The Bloch state induces quantum oscillations and linear cyclotron motion of carriers, which improves electron mobility and conductivity, reduces the series resistance and voltage of the laser element after lasing, and improves the slope efficiency and luminescence efficiency of the laser element; the exciton polaritons in the exciton polariton topological layer have strong metallic properties, which regulate the electrode spin Hall electron injection, improve the spin conductivity of the lower waveguide layer and the lower confinement layer, further reduce the series resistance and voltage, and increase the proportion of quasi-Fermi levels of holes and electrons that are pinned, regulate the symmetry breaking of the phase transition far from the equilibrium state, and eliminate the problems of discontinuous or sudden junction voltage jumps, conductivity jumps and series resistance sinks in the laser element. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural diagram of a semiconductor laser having an exciton-polariton topological layer according to an embodiment of the present invention;

[0023] Figure 2 This is a structural SIMS secondary ion mass spectrum of a semiconductor laser with an exciton-polariton topological layer according to an embodiment of the present invention;

[0024] Figure 3 This is a structural SIMS secondary ion mass spectrum of a semiconductor laser with an exciton-polariton topological layer according to an embodiment of the present invention.

[0025] Figure numerals: 100: substrate; 101: lower confinement layer; 102: lower waveguide layer; 103: active layer; 104: upper waveguide layer, 105: upper confinement layer, 106: exciton-polariton topological layer, 106a: first exciton-polariton topological layer, 106b: second exciton-polariton topological layer, 106c: third exciton-polariton topological layer. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] In order to solve the above problems, a semiconductor laser with an exciton-polariton topological layer provided in an embodiment of the present application will be introduced and explained in detail through the following specific embodiments.

[0028] Reference Figure 1-3 The present invention provides a semiconductor laser with an exciton polariton topological layer, 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, characterized in that the semiconductor laser has an exciton polariton topological layer 106; the exciton polariton topological layer 106 comprises a first exciton polariton topological layer 106a, a second exciton polariton topological layer 106b, and a third exciton polariton topological layer 106c, wherein the first exciton polariton topological layer 106a is located between the lower confinement layer 101 and the substrate 100, the second exciton polariton topological layer 106b is located inside the lower confinement layer 101, and the third exciton polariton topological layer 106c is located between the lower confinement layer 101 and the lower waveguide layer 102;

[0029] The Al / O element ratio distribution of the first exciton-polariton topological layer 106a has an approximate function y=sinx / x 2 The third quadrant curve distribution: The Si / H element ratio distribution of the first exciton polariton topological layer 106a has an approximate function y=ax 2 Curve distribution (a<0); The C / O element ratio distribution of the first exciton polariton topological layer 106a has an approximate function y=(b x -1) / (b x +1)(0<b<1);

[0030] The In / O element ratio distribution of the second exciton-polariton topological layer 106b has an approximate function y=cx 2Distribution (c<0) curve distribution; the Si / O element ratio distribution of the second exciton polariton topological layer 106b has an approximate function y=dx 2 Distribution (d<0) curve distribution; the C / O element ratio distribution of the second exciton polariton topological layer 106b has an approximate function y=x 2 / e x Curve distribution;

[0031] The Al / H element ratio distribution of the third exciton-polariton topological layer 106c has an approximate function y=l nx / x curve distribution; the Si / H element ratio of the third exciton-polariton topological layer 106c has an approximate function y=x 2 / e x Curve distribution; the C / O element ratio of the third exciton-polariton topological layer 106c has a curve distribution that approximates a linear function.

[0032] The exciton-polariton topological layer uses exciton-polaritons as a medium for particle number inversion, which enhances the stability of exciton-polariton quasiparticles, enhances the laser oscillation of the laser, and reduces the threshold current for particle number inversion at the laser energy level. At the same time, the exciton-polaritons in the exciton-polariton topological layer have strong metallic properties, which suppress electron scattering on the surface and interface, form repeated Bloch states to induce quantum oscillations and linear cyclotron motion of carriers, improve electron mobility and conductivity, reduce the series resistance and voltage of the laser element after lasing, and improve the slope efficiency and luminescence efficiency of the laser element.

[0033] The thickness of the first exciton polariton topological layer 106a is m: 20≤m≤80000 angstroms; the thickness of the second exciton polariton topological layer 106b is n: 50≤n≤90000 angstroms; the thickness of the third exciton polariton topological layer 106c is l: 10≤l≤70000 angstroms. The thicknesses of the first exciton polariton topological layer 106a, the second exciton polariton topological layer 106b, and the third exciton polariton topological layer 106c have the following relationship: l≤m≤n.

[0034] In the present invention, the well layer of the active layer 103 is any one or any combination of InGaN, InN, AlInN, and GaN, with a thickness of 10 to 80 angstroms, and the barrier layer of the active layer 103 is any one or any combination of GaN, AlGaN, AlInGaN, AlN, and AlInN, with a thickness of 10 to 120 angstroms; the active layer 103 is a periodic structure composed of well layers and barrier layers, and the number of periods is 3≥m≥1. The lower waveguide layer 102 is InGaN, with a thickness of 10 to 8000 angstroms; the upper waveguide layer 104 is InGaN, with a thickness of 10 to 8000 angstroms; the upper confinement layer 105 and the lower confinement layer 101 are any one or any combination of AlInGaN, AlInN, AlGaN, InGaN, GaN, AlInN, AlN, and InN, with a thickness of 10 to 9000 angstroms. The substrate 100 includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, sapphire / SiO 2 Composite substrate, Ga 2 O 3 , diamond, sapphire / Al N composite substrate, sapphire / SiN x , Sapphire / SiO 2 / SiN x Composite substrate, magnesium aluminum spinel MgAl 2 O 4 、MgO、ZnO、ZrB 2 、LiAlO 2 and LiGaO 2 Any type of composite substrate.

[0035] 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 semiconductor laser having an exciton polariton topological layer, 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: The semiconductor laser has an exciton polariton topological layer (106); the exciton polariton topological layer (106) comprises a first exciton polariton topological layer (106a), a second exciton polariton topological layer (106b) and a third exciton polariton topological layer (106c), the first exciton polariton topological layer (106a) is located between the lower confinement layer (101) and the substrate (100), the second exciton polariton topological layer (106b) is located inside the lower confinement layer (101), and the third exciton polariton topological layer (106c) is located between the lower confinement layer (101) and the lower waveguide layer (102); The Al / O element ratio distribution of the first exciton polariton topological layer (106a) has an approximate function y=sinx / x 2 The third quadrant curve distribution; the Si / H element ratio distribution of the first exciton polariton topological layer (106a) has an approximate function y=ax 2 Curve distribution (a<0); The C / O element ratio distribution of the first exciton polariton topological layer (106a) has an approximate function y=(b x -1) / (b x +1)(0<b<1); The In / O element ratio distribution of the second exciton polariton topological layer (106b) has an approximate function y=cx 2 The distribution (c<0) curve distribution; the Si / O element ratio distribution of the second exciton polariton topological layer (106b) has an approximate function y=dx 2 The distribution curve of the second exciton polariton topological layer (106b) has an approximate function y=x 2 / e x Curve distribution; The Al / H element ratio distribution of the third exciton polariton topological layer (106c) has an approximate function y=lnx / x curve distribution; the Si / H element ratio of the third exciton polariton topological layer (106c) has an approximate function y=x 2 / e x Curve distribution; the C / O element ratio of the third exciton polariton topological layer (106c) has a curve distribution that approximates a linear function.

2. The semiconductor laser having an exciton-polariton topological layer according to claim 1, characterized in that: The well layer of the active layer (103) is any one or any combination of InGaN, InN, AlInN, and GaN, and has a thickness of 10 to 80 angstroms; the barrier layer of the active layer (103) is any one or any combination of GaN, AlGaN, AlInGaN, AlN, and AlInN, and has a thickness of 10 to 120 angstroms; the active layer (103) is a periodic structure composed of well layers and barrier layers, and the number of periods is 3≥m≥1.

3. The semiconductor laser having an exciton-polariton topological layer according to claim 1, characterized in that: The thickness of the first exciton-polariton topological layer (106a) is m: 20≤m≤80000 angstroms; the thickness of the second exciton-polariton topological layer (106b) is n: 50≤n≤90000 angstroms; and the thickness of the third exciton-polariton topological layer (106c) is l: 10≤l≤70000 angstroms.

4. The semiconductor laser having an exciton-polariton topological layer according to claim 3, characterized in that: The thicknesses of the first exciton polariton topological layer (106a), the second exciton polariton topological layer (106b), and the third exciton polariton topological layer (106c) have the following relationship: l≤m≤n.

5. The semiconductor laser having an exciton-polariton topological layer according to claim 1, characterized in that: The lower waveguide layer (102) is InGaN with a thickness of 10 to 8000 angstroms; the upper waveguide layer (104) is InGaN with a thickness of 10 to 8000 angstroms; the upper confinement layer (105) and the lower confinement layer (101) are any one or any combination of AlInGaN, AlInN, AlGaN, InGaN, GaN, AlInN, AlN, and InN with a thickness of 10 to 9000 angstroms.

6. The semiconductor laser having an exciton-polariton topological layer according to claim 1, characterized in that: The substrate (100) includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, sapphire / SiO2 composite substrate, Ga2O3, diamond, 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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