CN-122026222-A - Gallium nitride-based semiconductor laser with graded hole mobility waveguide layer

CN122026222ACN 122026222 ACN122026222 ACN 122026222ACN-122026222-A

Abstract

The present disclosure relates to the technical field of semiconductor optoelectronic devices, and more particularly, to a gallium nitride-based semiconductor laser having a graded hole mobility waveguide layer, which sequentially includes, from bottom to top, a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer, and an upper confinement layer, wherein In composition distribution of the upper waveguide layer and the lower waveguide layer conforms to a predetermined function, so that the upper waveguide layer and the lower waveguide layer have graded hole mobility distribution, and the hole mobility distribution of the upper waveguide layer and the hole mobility distribution of the lower waveguide layer form a longitudinally graded hole mobility distribution.

Inventors

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

Assignees

安徽格恩半导体有限公司

Dates

Publication Date: 20260512
Application Date: 20260305

Claims (10)

1. The gallium nitride-based semiconductor laser with the graded hole mobility waveguide layer is characterized by comprising a substrate, a lower limiting layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer and an upper limiting layer from bottom to top in sequence; the In composition distribution of the upper waveguide layer and the lower waveguide layer accords with a preset function, so that the upper waveguide layer and the lower waveguide layer have gradual hole mobility distribution, the hole mobility distribution of the upper waveguide layer and the hole mobility distribution of the lower waveguide layer form longitudinal gradient distribution of the hole mobility distribution, and the longitudinal gradient distribution comprises eight-shaped distribution.
2. A gallium nitride-based semiconductor laser according to claim 1, wherein the fitted curve corresponding to the upper waveguide layer comprises a first upper waveguide layer curve and the fitted curve corresponding to the lower waveguide layer comprises a first lower waveguide layer curve; The first upper waveguide layer curve and the first lower waveguide layer curve respectively meet any one function distribution in ExpGrow1、ExpGrow2、Lorentz、Bradley、Allometric2、Allometric1、BiPhasic、FreundichEXT、Log3P1、Lop2P2、Biphasic、LogNormal、Extreme; wherein the first upper waveguide layer curve is a fitted curve of the In composition distribution of the upper waveguide layer, the first lower waveguide layer curve is a fitted curve of the In composition distribution of the lower waveguide layer, the In composition distribution including an In ion intensity distribution or an In atomic concentration distribution obtained by SIMS test.
3. A gallium nitride-based semiconductor laser according to claim 2, wherein the ExpGrow function distribution is: (1) In the formula (1), the components are as follows, As a baseline or an asymptotic value, Is the magnitude of the exponential term, As a parameter of the location of the feature, As a characteristic rate parameter of the device, A dependent variable that is a function of ExpGrow, x being an independent variable; the ExpGrow function distribution is: (2) In the formula (2), E is a baseline or asymptotic value, F 1 is a branch 1 amplitude, G 1 is a branch 1 characteristic position, H 1 is a branch 1 rate parameter, F 2 is a branch 2 amplitude, G 2 is a branch 2 characteristic position, H 2 is a branch 2 rate parameter, A dependent variable that is the ExpGrow2 function, x being the independent variable; The Lorentz function distribution is: (3) In the formula (3), J is a baseline background value, K is peak term integral intensity, L is half-width, M is peak position, As a dependent variable in the Lorentz function, x is an independent variable; The Bradley function distribution is: (4) in the formula (4), N is a scaling factor, P is a threshold parameter, Being a dependent variable of the Bradley function, x is an independent variable; the Allometric function distribution is: (5) in the formula (5), the amino acid sequence of the compound, As an upper-limit baseline parameter, a reference value, In order to attenuate the scaling factor, In order to provide an attenuation index, A dependent variable that is the Allometric2 function, x being the independent variable; the Log3P1 function distribution is: (6) in the formula (6), the amino acid sequence of the compound, As a baseline or saturation value, the value of the saturation, In order to attenuate the rate parameter of the light, As a parameter of the threshold value shift, A dependent variable of the Log3P1 function, wherein x is an independent variable; The LogNormal functions are distributed as follows: (7) in the formula (7), the amino acid sequence of the compound, As a baseline parameter, the parameter is a baseline parameter, As a magnitude factor, The spread program of the distribution is described for the logarithmic standard deviation, As a scale factor of the dimensions of the device, A dependent variable which is the LogNormal function, x being an independent variable; The extremee function distribution is: (8) In the formula (8), the amino acid sequence of the compound, As a baseline parameter, the parameter is a baseline parameter, As a magnitude factor, The value of the self-variable corresponding to the peak of the function is described for the position parameter, Describing the extent of stretching of the curve for the scale parameter, And x is an independent variable of the extremum function.
4. A gallium nitride-based semiconductor laser according to claim 2, wherein the fitted curve for the upper waveguide layer further comprises a second upper waveguide layer curve and the fitted curve for the lower waveguide layer further comprises a second lower waveguide layer curve; The second upper waveguide layer curve and the second lower waveguide layer curve respectively satisfy any one function distribution of ExpGrow, expGrow2, lorentz and Bradley; the second upper waveguide layer curve is a fitting curve of the effective state density distribution in the valence band of the upper waveguide layer, and the second lower waveguide layer curve is a fitting curve of the effective state density distribution in the valence band of the lower waveguide layer.
5. A gallium nitride-based semiconductor laser according to claim 2, wherein the fitted curve for the upper waveguide layer further comprises a third upper waveguide layer curve and the fitted curve for the lower waveguide layer further comprises a third lower waveguide layer curve; the third upper waveguide layer curve and the third lower waveguide layer curve respectively satisfy any one of the function distribution ExpGrow, expGrow, lorentz and Bradley; the third upper waveguide layer curve is a fitted curve of hole mobility distribution of the upper waveguide layer, and the third lower waveguide layer curve is a fitted curve of hole mobility distribution of the lower waveguide layer.
6. A gallium nitride-based semiconductor laser according to claim 2, wherein the fitted curve for the upper waveguide layer further comprises a fourth upper waveguide layer curve and the fitted curve for the lower waveguide layer further comprises a fourth lower waveguide layer curve; the fourth upper waveguide layer curve and the fourth lower waveguide layer curve respectively satisfy any one of the function distributions Allometric, allometric1, biPhasic and FreundichEXT; The fourth upper waveguide layer curve is a fitting curve of longitudinal phonon velocity distribution of the upper waveguide layer, the fourth lower waveguide layer curve is a fitting curve of longitudinal phonon velocity distribution of the lower waveguide layer, and the longitudinal phonon velocity distribution of the upper waveguide layer and the longitudinal phonon velocity distribution of the lower waveguide layer form the longitudinal phonon velocity distribution of V-shaped gradual change distribution.
7. A gallium nitride-based semiconductor laser according to claim 2, wherein the fitted curve for the upper waveguide layer further comprises a fifth upper waveguide layer curve and the fitted curve for the lower waveguide layer further comprises a fifth lower waveguide layer curve; the fifth upper waveguide layer curve and the fifth lower waveguide layer curve respectively meet any one function distribution of Log3P1, lop2P2 and Biphasic; The fifth upper waveguide layer curve is a fitting curve of energy distribution of polarized optical phonons of the upper waveguide layer, the fifth lower waveguide layer curve is a fitting curve of energy distribution of the polarized optical phonons of the lower waveguide layer, and the energy distribution of the polarized optical phonons of the upper waveguide layer and the energy distribution of the polarized optical phonons of the lower waveguide layer form energy distribution of the polarized optical phonons of V-shaped gradual change distribution.
8. A gallium nitride-based semiconductor laser according to claim 2, wherein the fitted curve for the upper waveguide layer further comprises a sixth upper waveguide layer curve and the fitted curve for the lower waveguide layer further comprises a sixth lower waveguide layer curve; The sixth upper waveguide layer curve and the sixth lower waveguide layer curve meet any one of function distribution of LogNormal and extremee; The sixth upper waveguide layer curve is a fitting curve of the separation energy distribution of the upper waveguide layer, the sixth lower waveguide layer curve is a fitting curve of the separation energy distribution of the lower waveguide layer, and the separation energy distribution of the upper waveguide layer and the separation energy distribution of the lower waveguide layer form the separation energy distribution of V-shaped gradual change distribution.
9. A gallium nitride-based semiconductor laser according to claim 2, wherein the fitted curve for the upper waveguide layer further comprises a seventh upper waveguide layer curve and the fitted curve for the lower waveguide layer further comprises a seventh lower waveguide layer curve; The seventh upper waveguide layer curve and the seventh lower waveguide layer curve satisfy any one of function distribution of LogNormal and extremee; The seventh upper waveguide layer curve is a fitting curve of Phillips ionization degree distribution of the upper waveguide layer, the seventh lower waveguide layer curve is a fitting curve of Phillips ionization degree distribution of the lower waveguide layer, and the Phillips ionization degree distribution of the upper waveguide layer and the Phillips ionization degree distribution of the lower waveguide layer form inverted V-shaped gradual change distribution.
10. The gallium nitride-based semiconductor laser of claim 1, wherein the substrate is a GaN single crystal substrate, the lower waveguide layer comprises InGaN or GaN/InGaN/GaN or any one or any combination of InGaN/GaN or GaN, the active layer comprises InGaN/GaN quantum wells, the upper waveguide layer comprises InGaN or GaN/InGaN/GaN or any one or any combination of InGaN/GaN or GaN, the electron blocking layer comprises any one or any combination of AlGaN, gaN, inGaN, alInGaN, alN, the upper confinement layer comprises any one or any combination of AlGaN, alN, gaN, alInN, alInGaN, and the lower confinement layer comprises any one or any combination of AlGaN, gaN, alN, inGaN, alInGaN, alInN; The lower waveguide layer is a GaN/InGaN combination, the thickness of the lower waveguide layer is 30-800 nm, the upper waveguide layer is InGaN, the thickness of the upper waveguide layer is 30-800 nm, the upper limiting layer is an AlGaN/AlGaN combination, the thickness of the upper limiting layer is 50-900 nm, the electron blocking layer is AlGaN, the thickness of the electron blocking layer is 0.5-80 nm, the thickness of the lower limiting layer is 500-5000 nm.

Description

Gallium nitride-based semiconductor laser with graded hole mobility waveguide layer Technical Field The present disclosure relates to the field of semiconductor optoelectronic devices, and more particularly to a gallium nitride-based semiconductor laser having a graded hole mobility 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 laser has various types and classification modes, and mainly comprises solid, gas, liquid, semiconductor, dye and other types. Compared with other types of lasers, 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. The laser is largely different from the nitride semiconductor light emitting diode. The laser is generated by stimulated radiation generated by carriers, the half-width of a spectrum is smaller, the brightness is higher, the output power of a single laser can be in W level, the output power of a nitride semiconductor light-emitting diode is spontaneous radiation, the output power of the single light-emitting diode is in mW level, the current density of the laser reaches KA/cm 2, and the current density of the laser is higher than that of the nitride light-emitting diode by more than 2 orders of magnitude, so that stronger electron leakage, more serious Auger recombination, stronger polarization effect and more serious electron-hole mismatch are caused, and the more serious efficiency attenuation Droop effect is caused. The light emitting diode emits self-transition radiation without external action, and the laser emits stimulated transition radiation, and the energy of the induced photon is equal to the energy level difference of electron transition, so as to generate the full coherent light of photon and induced photon. The laser device can perform laser emission only when the laser device needs to meet the requirement of the laser emission condition, the inversion distribution of carriers in an active area is required to be met, the stimulated 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 laser is output. There are a number of problems with current nitride semiconductor lasers. For example, the p-type semiconductor has a hole concentration far lower than the electron concentration and a hole mobility far lower than the electron mobility, and the quantum well polarized electric field promotes the problems of hole injection barrier, hole overflows the active layer, and the like, the hole injection is uneven and the efficiency is low, so that the electron holes in the quantum well are seriously asymmetric and unmatched, the electron leakage and the carrier are delocalized, the hole is more difficult to transport in the quantum well, the carrier injection is uneven, the gain is uneven, and meanwhile, the gain spectrum of the laser is widened, the peak gain is reduced, and the threshold current of the laser is increased and the slope efficiency is reduced. When electrons leak to the p-type semiconductor, a bipolar conductivity effect is formed, and when the carrier concentration of the active layer is saturated, the junction voltage at the threshold value is saturated, but the series resistance is increased, and the total voltage of the laser rises. According to the laser theory, after the laser emits stable laser light and is saturated, quasi-fermi energy levels of holes and electrons are pinned, injected carriers are completely converted into photon output, optical gain reaches saturation, junction voltage also reaches saturation, and carrier concentration in a cavity does not change along with current. The active layer is far away from symmetry break corresponding to equilibrium phase transition, so that discontinuous or abrupt change phenomenon of the laser occurs at the threshold, such as problems of conductivity jump, capacitance dip, junction voltage jump, series resistance dip, ideal factor jump and the like. Nitride semiconductor lasers also have heat loss problems. The Stokes shift loss formed by photon energy difference between pumping light and oscillating light is converted into heat, and the energy loss with coupling ratio of pumping energy level to upper laser energy level not being 1 is converted into heat, and the two together produce a large amount of waste heat, so that the temperature distribution of laser is uneven, and the thermal expansion and thermal stress distribution are caused to be uneven, and the temperature quenching, laser fracture, thermal lens effect and stress birefringence effect are generated. The