CN-121983850-A - Gallium nitride-based semiconductor laser with graded polarization waveguide layer

CN121983850ACN 121983850 ACN121983850 ACN 121983850ACN-121983850-A

Abstract

The invention provides a gallium nitride-based semiconductor laser with a graded polarization waveguide layer, wherein the lower waveguide layer comprises a first lower waveguide layer and a second lower waveguide layer, the second lower waveguide layer is a graded polarization lower waveguide layer, and the upper waveguide layer is a graded polarization upper waveguide layer. The fitting curve of the In ion intensity distribution or the In atomic concentration distribution, the fitting curve of the piezoelectric polarization coefficient and the fitting curve of the spontaneous polarization coefficient of the SIMS test of the waveguide layer under gradual polarization all meet ExpDec1 first-order exponential decay function distribution, and the fitting curve of the In ion intensity distribution or the In atomic concentration distribution, the fitting curve of the piezoelectric polarization coefficient and the fitting curve of the spontaneous polarization coefficient of the SIMS test of the waveguide layer on gradual polarization all meet ExpAssoc double-exponential correlation growth function distribution, so that the performance of the gallium nitride-based semiconductor laser is effectively improved.

Inventors

ZHENG JINJIAN
LAN JIABIN
HU ZHIYONG
ZHANG JIANGYONG
DENG HEQING
XUN FEILIN
CHEN WANJUN
ZHONG ZHIBAI
LIU ZIHAN
CAI XIN
LI XIAOQIN
YANG LIXUN

Assignees

安徽格恩半导体有限公司

Dates

Publication Date: 20260505
Application Date: 20260130

Claims (10)

1. The gallium nitride-based semiconductor laser with the graded polarization waveguide layer comprises a substrate, a lower limiting layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer, an upper limiting layer and a contact layer which are sequentially arranged from bottom to top, and is characterized in that the lower waveguide layer comprises a first lower waveguide layer and a second lower waveguide layer, the first lower waveguide layer is positioned below the second lower waveguide layer, the first lower waveguide layer is GaN, the second lower waveguide layer is the graded polarization lower waveguide layer, and the upper waveguide layer is the graded polarization upper waveguide layer; the fitting curve of In ion intensity distribution or In atomic concentration distribution of the SIMS test of the waveguide layer under the gradual polarization, the fitting curve of piezoelectric polarization coefficient and the fitting curve of spontaneous polarization coefficient all meet ExpDec first-order exponential decay function distribution; the fitting curve of In ion intensity distribution or In atom concentration distribution, the fitting curve of piezoelectric polarization coefficient and the fitting curve of spontaneous polarization coefficient of the SIMS test of the waveguide layer on the graded polarization all meet ExpAssoc double-index correlation growth function distribution.
2. The gallium nitride-based semiconductor laser with graded-polarization waveguide layer according to claim 1, wherein the fitted curve of the In ion intensity distribution or In atomic concentration distribution of the SIMS test of the graded-polarization waveguide layer satisfies ExpDec a1 first-order exponential decay function distribution of y 1 =A 1 *exp(-x 1 /t 1 )+B 1 , expDec a2 second-order exponential decay function, excpDec A3 third-order exponential decay function, a 1 is decay amplitude, t 1 is a characteristic decay time constant, B 1 is a baseline value or an asymptotic value, y 1 is the In ion intensity distribution or In atomic concentration of the SIMS test of the graded-polarization waveguide layer, x 1 is the thickness of the graded-polarization waveguide layer, wherein-30E 16 is equal to or less than a 1 ≤30E16,-0.9≤t 1 ≤0.9, 3E18≤B 1 is equal to or less than 35E20.
3. The gallium nitride-based semiconductor laser with graded-polarization waveguide layer according to claim 1, wherein the SIMS-tested In ion intensity profile or In atomic concentration profile of the graded-polarization upper waveguide layer is fitted to satisfy ExpAssoc double-exponential-dependent growth function profile y 2 =B 2 +A 2 (1-exp(-x 2 /t 2 ))+A 3 *(1-exp(-x 2 /t 3 )),B 2 as a baseline value, a 2 as the first-stage growth amplitude, t 2 as the first-stage characteristic time constant, a 3 as the second-stage growth amplitude, t 3 as the second-stage characteristic time constant, y 2 as the SIMS-tested In ion intensity profile or In atomic concentration of the graded-polarization upper waveguide layer, x 2 as the graded-polarization upper waveguide layer epitaxial layer thickness, wherein-20E 2. Ltoreq.b 2 ≤20E2,0≤A 2 ≤20E22,0≤A 3 ≤45E20,0≤t 2 ≤80,0≤t 3 . Ltoreq.130.
4. The gallium nitride-based semiconductor laser with graded-polarization waveguide layer according to claim 1, wherein the fitted curve of piezoelectric polarization coefficient distribution of the graded-polarization waveguide layer satisfies ExpDec a first-order exponential decay function distribution of y 3 =C*exp(-x 1 /D) +f, C is a decay amplitude, D is a characteristic decay time constant, F is a baseline value or an asymptotic value, y 3 is a piezoelectric polarization coefficient of the graded-polarization waveguide layer, x 1 is a thickness of the graded-polarization waveguide layer, wherein 0≤c≤20e-5, -0.9≤d≤0.9, and 0≤f≤15.
5. The gallium nitride-based semiconductor laser with graded-polarization waveguide layer according to claim 1, wherein the fitted curve of the self-polarization coefficient distribution of the graded-polarization waveguide layer satisfies ExpDec a first-order exponential decay function distribution of y 4 =G*exp(-x 1 /H) +j, G is a decay amplitude, H is a characteristic decay time constant, J is a baseline value or an asymptotic value, y 4 is the self-polarization coefficient of the graded-polarization waveguide layer, x 1 is the thickness of the graded-polarization waveguide layer, wherein 0≤g≤25E-7, -0.9≤h≤0.9, -0.5≤j≤5.
6. The gallium nitride-based semiconductor laser with graded-polarization waveguide layer according to claim 1, wherein the fitted curve of piezoelectric polarization coefficient of the graded-polarization upper waveguide layer satisfies ExpAssoc double-exponential-dependent growth function distribution y 5 =K+L(1-exp(-x 2 /M))+N*(1-exp(-x 2 /P)), K is a baseline value, L is an amplitude of the first-stage growth, M is a characteristic time constant of the first stage, N is an amplitude of the second-stage growth, P is a characteristic time constant of the second stage, y 5 is the piezoelectric polarization coefficient of the graded-polarization upper waveguide layer, x 2 is a piezoelectric polarization coefficient thickness, wherein 0≤k≤80, -60≤l. 60,0≤m≤8, -8≤n.8, and 0≤p≤15.
7. The gallium nitride-based semiconductor laser having a graded-polarization waveguide layer according to claim 1, wherein the fitted curve of the spontaneous polarization coefficient of the graded-polarization upper waveguide layer satisfies ExpAssoc double-exponentially-correlated growth function distribution y 6 =Q+R(1-exp(-x 2 /S))+U*(1-exp(-x 2 /V), Q is a base line value, R is an amplitude of the first-stage growth (maximum increment), S is a characteristic time constant of the first stage, U is an amplitude of the second-stage growth, V is a characteristic time constant of the second stage, y 6 is the spontaneous polarization coefficient of the graded-polarization upper waveguide layer, x 2 is the thickness of the graded-polarization upper waveguide layer, wherein 0≤q≤40, -40≤r≤40, 0≤s≤6, -80≤u≤ 80,500≤v.500000.
8. The gallium nitride-based semiconductor laser with graded polarization waveguide layer according to claim 1, wherein the substrate is a GaN single crystal substrate; The lower waveguide layer is any one or any combination of InGaN, gaN/InGaN/GaN, inGaN/GaN and GaN; The active layer is an InGaN/GaN quantum well; The upper waveguide layer is any one or any combination of InGaN, gaN/InGaN/GaN, inGaN/GaN and GaN; The electron blocking layer is any one or any combination of AlGaN, gaN, inGaN, alInGaN, alN.
9. The gallium nitride-based semiconductor laser with graded polarization waveguide layer of claim 1, wherein the lower waveguide layer is a combination of GaN and InGaN; The upper waveguide layer is InGaN; the upper limiting layer is an AlGaN/AlGaN combination; the electron blocking layer is AlGaN; the lower limiting layer is AlGaN/AlGaN or AlGaN/InGaN/AlGaN combination.
10. The gallium nitride-based semiconductor laser having a graded polarization waveguide layer according to claim 1, wherein the lower waveguide layer has a thickness of 300 to 8000 a; The upper waveguide layer has a thickness of 300 to 8000 a; the thickness of the upper limiting layer is 500 to 9000 angstroms; the electron blocking layer has a thickness of 5 to 800 a; the thickness of the lower limiting layer is 500 to 80000A.

Description

Gallium nitride-based semiconductor laser with graded polarization waveguide layer Technical Field The application relates to the field of semiconductor photoelectric devices, in particular to a gallium nitride-based semiconductor laser with a graded polarization waveguide layer. Background The laser is widely applied to the fields of laser display, laser television, laser projector, communication, medical treatment, weapon, guidance, distance measurement, spectrum analysis, cutting, precise welding, high-density optical storage and the like. The all-solid-state semiconductor laser has the advantages of small volume, high efficiency, light weight, good stability, long service life, simple and compact structure, miniaturization and the like compared with other types of lasers. The laser is largely different from the nitride semiconductor light emitting diode: 1) The laser is generated by stimulated radiation generated by carriers, the half-width of a spectrum is small, the brightness is high, the output power of a single laser can be in W level, the nitride semiconductor light-emitting diode is spontaneous radiation, and the output power of the single light-emitting diode is in mW level; 2) The current density of the laser reaches KA/cm2, which is more than 2 orders of magnitude higher than that of the nitride light-emitting diode, so that stronger electron leakage, more serious Auger recombination, stronger polarization effect and more serious electron-hole mismatch are caused, and more serious efficiency attenuation drop effect is caused; 3) The light-emitting diode emits self-transition radiation, no external effect exists, incoherent light transiting from a high energy level to a low energy level, the laser is stimulated transition radiation, the energy of an induced photon is equal to the energy level difference of electron transition, and the full coherent light of the photon and the induced photon is generated; 4) The principle is different that the light emitting diode generates radiation composite luminescence by the transition of electron holes to an active layer or a p-n junction under the action of external voltage, and the laser can be excited only by meeting the excitation condition, so that the inversion distribution of carriers in an active area is required to be met, the excited radiation light oscillates back and forth in a resonant cavity, the light is amplified by the propagation in a gain medium, the gain is larger than the loss by meeting the threshold condition, and finally the laser is output. The nitride semiconductor laser has the following problems that the GaN-based laser needs to promote the Al component due to the promotion of the optical field limiting effect, but the promotion of the Al component of the upper limiting layer reduces the ionization efficiency of Mg, so that the concentration of holes is too low and the injection of holes is insufficient. Disclosure of Invention In order to solve one of the technical problems, the invention provides a gallium nitride-based semiconductor laser with a graded polarization waveguide layer. The embodiment of the invention provides a gallium nitride-based semiconductor laser with a graded polarization waveguide layer, which comprises a substrate, a lower limiting layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electronic blocking layer, an upper limiting layer and a contact layer which are sequentially arranged from bottom to top, wherein the lower waveguide layer comprises a first lower waveguide layer and a second lower waveguide layer, the first lower waveguide layer is positioned below the second lower waveguide layer, the first lower waveguide layer is GaN, the second lower waveguide layer is a graded polarization lower waveguide layer, and the upper waveguide layer is a graded polarization upper waveguide layer; the fitting curve of In ion intensity distribution or In atomic concentration distribution of the SIMS test of the waveguide layer under the gradual polarization, the fitting curve of piezoelectric polarization coefficient and the fitting curve of spontaneous polarization coefficient all meet ExpDec first-order exponential decay function distribution; the fitting curve of In ion intensity distribution or In atom concentration distribution, the fitting curve of piezoelectric polarization coefficient and the fitting curve of spontaneous polarization coefficient of the SIMS test of the waveguide layer on the graded polarization all meet ExpAssoc double-index correlation growth function distribution. Preferably, the fitted curve of the In ion intensity distribution or In atomic concentration distribution of the SIMS test of the waveguide layer under the graded polarization satisfies that ExpDec first-order exponential decay function distribution is any one of y 1=A1*exp(-x1/t1)+B1, expDec2 second-order exponential decay function and ExcpDec third-order exponential decay function, A 1 is decay amp