Semiconductor laser with lower waveguide layer for suppressing heat fading

Abstract

The invention discloses a semiconductor laser with a lower waveguide layer for suppressing heat fading, which sequentially comprises a substrate, a lower coating layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer and an upper coating layer from bottom to top, the waveguide layer under the low oscillation threshold is any one or any combination of an InGaN / GaN superlattice, an InGaN / AlGaN superlattice, an InGaN / AlInGaN superlattice, an InGaN / AlInN superlattice, a GaN / AlGaN superlattice, a GaN / AlInGaN superlattice and a GaN / AlN superlattice, and the thickness of the waveguide layer under the low oscillation threshold is 5-1000 nm. The waveguide side wall scattering loss and quantum well absorption loss of the laser are reduced, the internal light absorption loss of the laser is reduced, heat fading caused by non-radiative recombination is inhibited, the threshold current of the laser is reduced, and the slope efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor optoelectronic devices, in particular to a semiconductor laser with a lower waveguide layer that suppresses thermal decay. 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. 1) Lasers are generated by stimulated emission 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, with the output power of a single light-emitting diode in the mW level. 2) The operating current density of lasers reaches 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; 3) The light-emitting diode spontaneously radiates incoherent light from high energy level to low energy level without external influence, while the laser is stimulated transition radiation. The energy of the induced photon should be equal to the difference in energy levels of the electron transition, generating completely coherent light of the photon and the induced photon; 4) The principle is different: the light-emitting diode is under the action of external voltage, and the electron-hole transition to the active layer or pn junction generates radiative recombination and luminescence, while the laser needs to meet the lasing conditions before it can be lased. The carrier inversion distribution in the active area must be met. The stimulated radiation light oscillates back and forth in the resonant cavity, and the propagation in the gain medium amplifies the light. The threshold condition is met so that the gain is greater than the loss, and finally the laser is output.

[0004] Nitride semiconductor lasers have the following problems: the laser's optical waveguide impurity absorption loss is high, causing internal optical loss to increase, resulting in a decrease in the laser's slope efficiency and an increase in the threshold current; the electron-hole asymmetry and mismatch in the quantum well are serious, electron leakage and carrier delocalization occur, hole transport in the quantum well is more difficult, carrier injection is uneven, and gain is uneven, which widens the laser gain spectrum and reduces the peak gain, resulting in an increase in the laser's threshold current; non-radiative recombination losses and free carrier absorption in the active region of the violet laser generate a large amount of heat. If the laser has low thermal conductivity, poor heat dissipation, and poor temperature characteristics, it will aggravate the thermal mismatch between the semiconductor epitaxial layers, leading to problems such as increased threshold current, decreased output light power and slope efficiency. Summary of the Invention

[0005] The present invention proposes a semiconductor laser with a lower waveguide layer that suppresses thermal decay, improves the electron drift rate of the lower waveguide layer and the active layer, improves the carrier filling efficiency of the stimulated emission energy band, reduces the laser waveguide sidewall scattering loss and quantum well absorption loss, reduces the internal light absorption loss of the laser, suppresses thermal decay caused by non-radiative recombination, reduces the threshold current of the laser and improves the slope efficiency.

[0006] The present invention provides a semiconductor laser with a lower waveguide layer for suppressing thermal decay, which comprises, from bottom to top, a substrate, a lower cladding layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer, and an upper cladding layer. The lower waveguide layer is a low oscillation threshold lower waveguide layer, and the low oscillation threshold lower waveguide layer is any one or any combination of InGaN, GaN, InN, AlInGaN, AlInN, AlN, InGaN / GaN superlattice, InGaN / AlGaN superlattice, InGaN / AlInGaN superlattice, InGaN / AlInN superlattice, GaN / AlGaN superlattice, GaN / AlInGaN superlattice, and GaN / AlN superlattice, and has a thickness of 5 to 1000 nm.

[0007] Preferably, the descending angle of the peak position of the saturated electron drift rate of the waveguide layer under the low oscillation threshold toward the lower cladding layer is α, the rising angle of the valley position of the absorption coefficient of the waveguide layer under the low oscillation threshold toward the lower cladding layer is β, the rising angle of the valley position of the polarization optical phonon energy of the waveguide layer under the low oscillation threshold toward the lower cladding layer is γ, and the rising angle of the valley position of the transverse sound velocity of the waveguide layer under the low oscillation threshold toward the lower cladding layer is θ, wherein: 40°≤γ≤θ≤α≤β≤≤90°.

[0009] Preferably, the rising angle of the valley position of the saturated electron drift velocity of the waveguide layer at the low oscillation threshold toward the active layer is δ, the descending angle of the peak position of the absorption coefficient of the waveguide layer at the low oscillation threshold toward the active layer is σ, the descending angle of the peak position of the polarization optical phonon energy of the waveguide layer at the low oscillation threshold toward the active layer is φ, and the descending angle of the peak position of the transverse sound velocity of the waveguide layer at the low oscillation threshold toward the active layer is ψ, wherein: 45°≤ψ≤φ≤δ≤σ≤90°.

[0010] Preferably, the descending angle of the peak position of the saturated electron drift velocity of the waveguide layer under the low oscillation threshold toward the lower cladding layer, the rising angle of the valley position of the absorption coefficient, polarimetric phonon energy, and transverse sound velocity of the waveguide layer under the low oscillation threshold toward the lower cladding layer, the rising angle of the valley position of the saturated electron drift velocity of the waveguide layer under the low oscillation threshold toward the active layer, and the descending angle of the peak position of the absorption coefficient, polarimetric phonon energy, and transverse sound velocity of the waveguide layer under the low oscillation threshold toward the active layer have the following relationship: 40°≤γ≤ψ≤θ≤φ≤α≤δ≤β≤σ≤90°.

[0011] Preferably, the saturated electron drift velocity distribution of the waveguide layer at the low oscillation threshold has a function y=e x / cosx third quadrant curve distribution.

[0012] Preferably, the polari-optical phonon energy distribution of the waveguide layer at the low oscillation threshold has a function y=x / e x Curve distribution; the absorption coefficient distribution of the waveguide layer under the low oscillation threshold has a function y=e x / x 2 Curve distribution; the transverse sound velocity distribution of the waveguide layer under the low oscillation threshold has a function y=x / e x Curved distribution.

[0013] Preferably, the upper waveguide layer is any one or any combination of InGaN, GaN, InN, AlInGaN, AlInN, AlN, InGaN / GaN superlattice, InGaN / AlGaN superlattice, InGaN / AlInGaN superlattice, InGaN / AlInN superlattice, GaN / AlGaN superlattice, GaN / AlInGaN superlattice, and GaN / AlN superlattice, with a thickness of 5 to 1000 nm.

[0014] Preferably, the well layer of the active 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 has a thickness of 10 to 150 angstroms. The barrier layer of the active layer is any one or any combination of GaN, InGaN, InN, AlInN, AlGaN, AlInGaN, AlN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, InGaAsN, AlInAs, AlInP, AlGaP, InGaP, GaSb, InSb, InAs, InAsSb, AlGaSb, AlSb, InGaSb, AlGaAsSb, InGaAsSb, SiC, Ga2O3, BN, and diamond, with a thickness of 10 to 200 angstroms.

[0015] Preferably, the lower cladding layer, the electron blocking layer and the upper cladding 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 and diamond.

[0016] Preferably, the substrate includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite substrate, Mo, TiW, CuW, Cu, sapphire / AlN composite substrate, diamond, graphene, sapphire / SiN x , sapphire / SiO2 / SiN x Composite substrate, sapphire / SiN x Any one of a / SiO2 composite substrate, a magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2 and LiGaO2 composite substrate.

[0017] Compared with the prior art, the embodiments of the present invention provide a semiconductor laser with a lower waveguide layer that suppresses thermal decay, which has the following beneficial effects: the present invention designs the change angle and distribution of the saturated electron drift rate and absorption coefficient, improves the electron drift rate of the lower waveguide layer and the active layer, improves the carrier filling efficiency of the stimulated emission energy band, and reduces the laser waveguide sidewall scattering loss and quantum well absorption loss, reduces the internal light absorption loss of the laser, suppresses thermal decay caused by non-radiative recombination, reduces the threshold current of the laser and improves the slope efficiency; at the same time, the present invention designs the change angle and distribution of the polarization optical phonon energy and the transverse sound velocity, regulates the phonon transport and transmission of the laser, reduces Joule heat loss and carrier absorption loss, reduces the junction temperature of the laser and the junction temperature rise, improves thermal decay, further reduces the threshold current and improves the photoelectric conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 1 is a schematic structural diagram of a semiconductor laser having a lower waveguide layer for suppressing thermal decay according to an embodiment of the present invention;

[0019] Figure 2 This is a SIMS secondary ion mass spectrum of the structure of a semiconductor laser with a lower waveguide layer that suppresses thermal decay according to an embodiment of the present invention;

[0020] Figure 3 This is a SIMS secondary ion mass spectrum of the structure of a semiconductor laser with a lower waveguide layer that suppresses thermal decay according to an embodiment of the present invention;

[0021] Figure 4 This is a TEM lens electron microscope image of a semiconductor laser with a lower waveguide layer that suppresses thermal decay according to an embodiment of the present invention;

[0022] Figure 5 This is a TEM lens electron microscope image (partial magnification) of a semiconductor laser with a lower waveguide layer that suppresses thermal decay according to an embodiment of the present invention;

[0023] Figure 6 This is a TEM lens electron microscope image (partial magnification) of a semiconductor laser with a lower waveguide layer that suppresses thermal decay according to an embodiment of the present invention;

[0024] Reference numerals: 100: substrate; 101: lower cladding layer; 102: lower waveguide layer; 103: active layer; 104: upper waveguide layer, 105: electron blocking layer, 106: upper cladding layer. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0026] In order to solve the above problems, a semiconductor laser with a lower waveguide layer that suppresses thermal degradation provided by an embodiment of the present application will be introduced and explained in detail through the following specific embodiments.

[0027] Reference Figure 1-6 The present invention provides a semiconductor laser with a lower waveguide layer for suppressing thermal degradation, which includes, from bottom to top, a substrate 100, a lower cladding layer 101, a lower waveguide layer 102, an active layer 103, an upper waveguide layer 104, an electron blocking layer 105, and an upper cladding layer 106. The lower waveguide layer 102 is a low oscillation threshold lower waveguide layer 102, and the low oscillation threshold lower waveguide layer 102 is any one or any combination of InGaN, GaN, InN, AlInGaN, AlInN, AlN, InGaN / GaN superlattice, InGaN / AlGaN superlattice, InGaN / AlInGaN superlattice, InGaN / AlInN superlattice, GaN / AlGaN superlattice, GaN / AlInGaN superlattice, and GaN / AlN superlattice, and has a thickness of 5 to 1000 nm.

[0028] In the present invention, Figure 2-3 As shown, the descending angle of the peak position of the saturated electron drift velocity of the waveguide layer 102 at the low oscillation threshold toward the lower cladding layer 101 is α, the rising angle of the valley position of the absorption coefficient of the waveguide layer 102 at the low oscillation threshold toward the lower cladding layer 101 is β, the rising angle of the valley position of the polarization phonon energy of the waveguide layer 102 at the low oscillation threshold toward the lower cladding layer 101 is γ, and the rising angle of the valley position of the transverse sound velocity of the waveguide layer 102 at the low oscillation threshold toward the lower cladding layer 101 is θ, wherein: 40°≤γ≤θ≤α≤β≤≤90°.

[0029] In the present invention, the rising angle of the valley position of the saturated electron drift velocity of the waveguide layer 102 at the low oscillation threshold toward the active layer 103 is δ, the falling angle of the peak position of the absorption coefficient of the waveguide layer 102 at the low oscillation threshold toward the active layer 103 is σ, the falling angle of the peak position of the polarization phonon energy of the waveguide layer 102 at the low oscillation threshold toward the active layer 103 is φ, and the falling angle of the peak position of the transverse sound velocity of the waveguide layer 102 at the low oscillation threshold toward the active layer 103 is ψ, wherein: 45°≤ψ≤φ≤δ≤σ≤90°.

[0030] In the present invention, the descending angle of the peak position of the saturated electron drift velocity of the waveguide layer 102 at the low oscillation threshold toward the lower cladding layer 101, the rising angle of the valley position of the absorption coefficient, polarimetric phonon energy, and transverse sound velocity of the waveguide layer 102 at the low oscillation threshold toward the lower cladding layer 101, the rising angle of the valley position of the saturated electron drift velocity of the waveguide layer 102 at the low oscillation threshold toward the active layer 103, and the descending angle of the peak position of the absorption coefficient, polarimetric phonon energy, and transverse sound velocity of the waveguide layer 102 at the low oscillation threshold toward the active layer 103 have the following relationship: 40°≤γ≤ψ≤θ≤φ≤α≤δ≤β≤σ≤90°.

[0031] In the present invention, the saturated electron drift velocity distribution of the waveguide layer 102 at the low oscillation threshold has a function y=e x The polarization phonon energy distribution of the waveguide layer 102 at the low oscillation threshold has the function y=x / e x Curve distribution; the absorption coefficient distribution of the waveguide layer 102 under the low oscillation threshold has a function y=e x / x 2 Curve distribution; The transverse sound velocity distribution of the waveguide layer 102 under the low oscillation threshold has a function y=x / e x Curved distribution.

[0032] In summary, if Figure 4-6 As shown, the present invention designs the change angle and distribution of the saturated electron drift rate and absorption coefficient, improves the electron drift rate of the lower waveguide layer 102 and the active layer 103, improves the carrier filling efficiency of the stimulated radiation energy band, and reduces the laser waveguide side wall scattering loss and quantum well absorption loss, reduces the internal light absorption loss of the laser, suppresses the thermal decay caused by non-radiative recombination, reduces the threshold current of the laser and improves the slope efficiency; at the same time, the present invention designs the change angle and distribution of the polarization optical phonon energy and the transverse sound velocity, regulates the phonon transport and transmission of the laser, reduces Joule heat loss and carrier absorption loss, reduces the junction temperature of the laser and the junction temperature rise, improves thermal decay, further reduces the threshold current and improves the photoelectric conversion efficiency. As shown in the following table:

[0033]

[0034]

[0035] In the present invention, the upper waveguide layer 104 is any one or any combination of InGaN, GaN, InN, AlInGaN, AlInN, AlN, InGaN / GaN superlattice, InGaN / AlGaN superlattice, InGaN / AlInGaN superlattice, InGaN / AlInN superlattice, GaN / AlGaN superlattice, GaN / AlInGaN superlattice, and GaN / AlN superlattice, and has a thickness of 5 to 1000 nm.

[0036] In the present invention, the well layer of the active layer 103 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 has a thickness of 10 to 150 μm. angstroms, the barrier layer of the active layer 103 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 to 200 angstroms.

[0037] In the present invention, the lower cladding layer 101, the electron blocking layer 105, and the upper cladding layer 106 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, and diamond.

[0038] In the present invention, the substrate 100 includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite substrate, Mo, TiW, CuW, Cu, sapphire / AlN composite substrate, diamond, graphene, sapphire / SiN x , sapphire / SiO2 / SiN x Composite substrate, sapphire / SiN x Any one of a / SiO2 composite substrate, a magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2 and LiGaO2 composite substrate.

[0039] 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 a lower waveguide layer for suppressing thermal decay, comprising, from bottom to top, a substrate (100), a lower cladding layer (101), a lower waveguide layer (102), an active layer (103), an upper waveguide layer (104), an electron blocking layer (105), and an upper cladding layer (106), characterized in that: The lower waveguide layer (102) is a low oscillation threshold lower waveguide layer (102), and the low oscillation threshold lower waveguide layer (102) is any one or any combination of InGaN, GaN, InN, AlInGaN, AlInN, AlN, InGaN / GaN superlattice, InGaN / AlGaN superlattice, InGaN / AlInGaN superlattice, InGaN / AlInN superlattice, GaN / AlGaN superlattice, GaN / AlInGaN superlattice, and GaN / AlN superlattice, and has a thickness of 5 to 1000 nm.

2. A semiconductor laser having a lower waveguide layer for suppressing thermal decay according to claim 1, characterized in that: The peak position of the saturated electron drift rate of the waveguide layer (102) at the low oscillation threshold has a descending angle α toward the lower cladding layer (101), the valley position of the absorption coefficient of the waveguide layer (102) at the low oscillation threshold has a rising angle β toward the lower cladding layer (101), the valley position of the polarized optical phonon energy of the waveguide layer (102) at the low oscillation threshold has a rising angle γ toward the lower cladding layer (101), and the valley position of the transverse sound velocity of the waveguide layer (102) at the low oscillation threshold has a rising angle θ toward the lower cladding layer (101), wherein: 40°≤γ≤θ≤α≤β≤≤90°.

3. The semiconductor laser having a lower waveguide layer for suppressing thermal decay according to claim 1, characterized in that: The valley position of the saturated electron drift rate of the waveguide layer (102) at the low oscillation threshold has a rising angle δ toward the active layer (103), the peak position of the absorption coefficient of the waveguide layer (102) at the low oscillation threshold has a descending angle σ toward the active layer (103), the peak position of the polarization optical phonon energy of the waveguide layer (102) at the low oscillation threshold has a descending angle φ toward the active layer (103), and the peak position of the transverse sound velocity of the waveguide layer (102) at the low oscillation threshold has a descending angle ψ toward the active layer (103), wherein: 45°≤ψ≤φ≤δ≤σ≤90°.

4. A semiconductor laser having a lower waveguide layer for suppressing thermal decay according to claim 2 or 3, characterized in that: The descending angle of the peak position of the saturated electron drift velocity of the waveguide layer (102) at the low oscillation threshold toward the cladding layer (101), the rising angle of the valley position of the absorption coefficient, polarized optical phonon energy, and transverse sound velocity of the waveguide layer (102) at the low oscillation threshold toward the cladding layer (101), the rising angle of the valley position of the saturated electron drift velocity of the waveguide layer (102) at the low oscillation threshold toward the active layer (103), and the descending angle of the peak position of the absorption coefficient, polarized optical phonon energy, and transverse sound velocity of the waveguide layer (102) at the low oscillation threshold toward the active layer (103) have the following relationship: 40°≤γ≤ψ≤θ≤φ≤α≤δ≤β≤σ≤90°.

5. The semiconductor laser having a lower waveguide layer for suppressing thermal decay according to claim 1, characterized in that: The saturated electron drift velocity distribution of the waveguide layer (102) at the low oscillation threshold has a function y=e x / cosx third quadrant curve distribution.

6. The semiconductor laser having a lower waveguide layer for suppressing thermal decay according to claim 1, characterized in that: The polarization optical phonon energy distribution of the waveguide layer (102) at the low oscillation threshold has a function y=x / e x Curve distribution; the absorption coefficient distribution of the waveguide layer (102) under the low oscillation threshold has a function y=e x / x 2 Curve distribution; the transverse sound velocity distribution of the waveguide layer (102) under the low oscillation threshold has a function y=x / e x Curved distribution.

7. The semiconductor laser having a lower waveguide layer for suppressing thermal decay according to claim 1, characterized in that: The upper waveguide layer (104) is any one or any combination of InGaN, GaN, InN, AlInGaN, AlInN, AlN, InGaN / GaN superlattice, InGaN / AlGaN superlattice, InGaN / AlInGaN superlattice, InGaN / AlInN superlattice, GaN / AlGaN superlattice, GaN / AlInGaN superlattice, and GaN / AlN superlattice, and has a thickness of 5 to 1000 nm.

8. The semiconductor laser having a lower waveguide layer for suppressing thermal decay according to claim 1, characterized in that: The well layer of the active layer (103) 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 has a thickness of 10 to 150 angstroms. The barrier layer of the active layer (103) 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 has a thickness of 10 to 200 angstroms.

9. The semiconductor laser having a lower waveguide layer for suppressing thermal decay according to claim 1, characterized in that: The lower cladding layer (101), the electron blocking layer (105), and the upper cladding layer (106) 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, and diamond.

10. The semiconductor laser having a lower waveguide layer for suppressing thermal decay according to claim 1, characterized in that: The substrate (100) includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, InAs, GaSb, sapphire / SiO2 composite substrate, Mo, TiW, CuW, Cu, sapphire / AlN composite substrate, diamond, graphene, sapphire / SiN x , Sapphire / SiO2 / SiN x Composite substrate, sapphire / SiN x Any one of a / SiO2 composite substrate, a magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2 and LiGaO2 composite substrate.

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