Semiconductor laser with a thermoelectric figure of merit control layer

Abstract

The application provides a semiconductor laser with a thermoelectric optimal value control layer, which comprises, from bottom to top, 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, and a thermoelectric optimal value control layer is arranged between the substrate and the lower limiting layer; the Si doping concentration of the thermoelectric optimal value control layer is greater than the Si doping concentration of the substrate and the lower limiting layer, the C impurity concentration of the thermoelectric optimal value control layer is less than the C impurity concentration of the lower limiting layer, and the H impurity concentration of the thermoelectric optimal value control layer is less than or equal to the H impurity concentration of the lower limiting layer. The application improves the mode gain, power factor and slope efficiency of the laser system, and the slope efficiency is improved by 125%, the optical power is improved by 37%, and the limiting factor is improved by 50%.

Description

Technical Field

[0001] This application relates to the field of semiconductor optoelectronic devices, and more particularly to a semiconductor laser with a thermoelectric figure of merit control layer. Background Technology

[0002] Lasers are widely used in laser displays, laser TVs, laser projectors, communications, medical applications, weaponry, guidance, ranging, spectral analysis, cutting, precision welding, and high-density optical storage. There are many types of lasers, and they can be classified in various ways, mainly including solid-state, gas, liquid, semiconductor, and dye lasers. Compared with other types of lasers, all-solid-state semiconductor lasers have advantages such as small size, high efficiency, light weight, good stability, long lifespan, simple and compact structure, and miniaturization.

[0003] Lasers and nitride semiconductor light-emitting diodes (LEDs) differ significantly:

[0004] 1) Lasers are generated by stimulated emission of charge carriers. They have a small half-width at half-maximum and very high brightness. The output power of a single laser can be in the W range. In contrast, nitride semiconductor light-emitting diodes are spontaneously emitted, and the output power of a single light-emitting diode is in the mW range.

[0005] 2) The operating current density of the laser reaches KA / cm². 2 The efficiency is more than two orders of magnitude higher than that of nitride light-emitting diodes, resulting in stronger electron leakage, more severe Auger recombination, stronger polarization effect, and more severe electron-hole mismatch, leading to more severe efficiency degradation and the Droop effect.

[0006] 3) Light-emitting diodes emit spontaneous transition radiation, which is incoherent light that transitions from a high energy level to a low energy level without external influence. In contrast, lasers emit stimulated transition radiation, where the energy of the induced photon should be equal to the energy difference of the electron transition, producing coherent light that is identical to the induced photon.

[0007] 4) Different principles: Light emission diodes emit light by radiative recombination when electrons and holes jump to quantum wells or pn junctions under the action of external voltage. Lasers, on the other hand, require certain lasing conditions to be met before they can emit light. This requires the carriers in the active region to be reversed, the stimulated emission light to oscillate back and forth in the resonant cavity, and the light to be amplified by propagation in the gain medium. When the threshold condition is met, the gain is greater than the loss, and finally, laser light is output.

[0008] Nitride semiconductor lasers have the following problems:

[0009] 1) Large internal lattice mismatch and strain lead to strong polarization effect, and the strong Stark effect of quantum confinement in QCSE limits the improvement of laser electro-lasing gain;

[0010] 2) High internal defect density and unsatisfactory crystal quality result in low quantum well luminescence efficiency;

[0011] 3) The increased band gap in the valence band of the laser makes it more difficult for holes to transport in the quantum well, resulting in non-uniform carrier injection and non-uniform gain.

[0012] 4) The refractive index dispersion of the laser and the confinement factor decrease with increasing wavelength, resulting in a decrease in the mode gain of the laser. Summary of the Invention

[0013] To address one of the aforementioned technical problems, the present invention provides a semiconductor laser with a thermoelectric figure of merit control layer.

[0014] This invention provides a semiconductor laser with a thermoelectric figure of merit control layer, comprising, 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 a thermoelectric figure of merit control layer is disposed between the substrate and the lower confinement layer;

[0015] The Si doping concentration of the thermoelectric figure of merit control layer is greater than the Si doping concentration of the substrate and the lower confinement layer, the C impurity concentration of the thermoelectric figure of merit control layer is less than the C impurity concentration of the lower confinement layer, and the H impurity concentration of the thermoelectric figure of merit control layer is less than or equal to the H impurity concentration of the lower confinement layer.

[0016] Preferably, in the thermoelectric figure of merit control layer, the Si doping concentration is ≥ H impurity concentration ≥ C impurity concentration.

[0017] Preferably, the Si doping concentration of the thermoelectric figure-of-figure control layer is greater than 1E19cm⁻¹. -3 .

[0018] Preferably, the C impurity concentration of the thermoelectric figure of merit control layer is 1E15cm⁻¹. -3 Up to 1E17cm -3 .

[0019] Preferably, the H impurity concentration of the thermoelectric figure of merit control layer is 5E16 cm⁻¹. -3 Up to 5E17cm -3 .

[0020] Preferably, the thermoelectric figure of merit control layer is any one or any combination of AlGaN, AlInGaN, GaN, AlInN, and InGaN, with a thickness of 10 to 50,000 angstroms.

[0021] Preferably, the lower confinement layer, lower waveguide layer, upper waveguide layer, electron blocking layer, and upper confinement layer include any one or any combination of GaN, AlGaN, InGaN, AlInGaN, AlN, InN, AlInN, SiC, Ga2O3, BN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, AlInAs, AlInP, AlGaP, and InGaP.

[0022] Preferably, the active layer is a periodic structure composed of a well layer and a barrier layer, with a period of m: 1 ≤ m ≤ 3; the well layer of the active layer is any one or any combination of GaN, InGaN, InN, AlInN, AlInGaN, and AlGaN, with a thickness of p: 5 ≤ p ≤ 100 angstroms; the barrier layer of the active layer is any one or any combination of GaN, InGaN, InN, AlInN, AlInGaN, and AlN, with a thickness of q: 10 ≤ q ≤ 200 angstroms.

[0023] Preferably, the thickness of the lower waveguide layer is x: 10 ≤ x ≤ 9000 angstroms; the thickness of the upper waveguide layer is y: 10 ≤ y ≤ 9000 angstroms; the thickness of the lower confinement layer is z: 10 ≤ z ≤ 90000 angstroms; and the thicknesses of the upper confinement layer and the electron blocking layer are both n: 10 ≤ n ≤ 80000 angstroms.

[0024] Preferably, the substrate comprises sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, sapphire / SiO2 composite substrate, sapphire / AlN composite substrate, or sapphire / SiN composite substrate. x Any one of the following composite substrates: magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2, and LiGaO2.

[0025] The beneficial effects of this invention are as follows: By setting a thermoelectric figure of merit control layer between the substrate and the lower confinement layer, and the interface concentration difference between the thermoelectric figure of merit control layer and the substrate and the lower confinement layer of Si doping concentration, H impurity concentration and C impurity concentration, a multi-level structure from atomic-scale dislocations to micro-scale grain boundaries is constructed. This causes the zero-dimensional cavitation defects extending from the substrate to evolve into high-dimensional defects, reducing phonon scattering in multiple frequency bands, reducing carrier scattering, improving the thermal conductivity of the lattice, synergistically controlling electron and phonon transport, improving hole transport efficiency in the active layer, improving the refractive index dispersion of the laser, and improving the mode gain, power factor and slope efficiency of the laser system. The slope efficiency is improved by 125%, the optical power by 37%, and the confinement factor by 50%. Attached Figure Description

[0026] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0027] Figure 1 This is a schematic diagram of the structure of a semiconductor laser with a thermoelectric figure of merit control layer according to an embodiment of the present invention;

[0028] Figure 2 This is a SIMS secondary ion mass spectrum of a semiconductor laser with a thermoelectric figure of merit control layer as described in an embodiment of the present invention.

[0029] Figure label:

[0030] 100. Substrate; 101. Lower confinement layer; 102. Lower waveguide layer; 103. Active layer; 104. Upper waveguide layer; 105. Electron blocking layer; 106. Upper confinement layer; 107. Thermoelectric figure of merit control layer. Detailed Implementation

[0031] To make the technical solutions and advantages of the embodiments of this application clearer, the exemplary embodiments of this application will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not an exhaustive list of all embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0032] like Figure 1 As shown, this embodiment proposes a semiconductor laser with a thermoelectric figure of merit control layer, including a substrate 100, a lower confinement layer 101, a lower waveguide layer 102, an active layer 103, an upper waveguide layer 104, an electron blocking layer 105, and an upper confinement layer 106 arranged sequentially from bottom to top, and a thermoelectric figure of merit control layer 107 disposed between the substrate 100 and the lower confinement layer 101.

[0033] Specifically, such as Figure 2 As shown, in this embodiment, the Si doping concentration, C impurity concentration, and H impurity concentration in the thermoelectric figure of merit control layer 107 are different from those in the substrate 100 and the lower confinement layer 101, specifically as follows:

[0034] The Si doping concentration of the thermoelectric figure control layer 107 is greater than that of the substrate 100 and the lower confinement layer 101.

[0035] The C impurity concentration in the thermoelectric figure control layer 107 is less than the C impurity concentration in the lower confinement layer 101;

[0036] The H impurity concentration of the thermoelectric figure of merit control layer 107 is less than or equal to the H impurity concentration of the lower confinement layer 101.

[0037] This embodiment controls the Si doping concentration, C impurity concentration, and H impurity concentration of the thermoelectric figure of merit control layer 107 to create an interfacial concentration difference of Si doping concentration, C impurity concentration, and H impurity concentration between the thermoelectric figure of merit control layer 107, the substrate 100, and the lower confinement layer 101. This constructs a multi-level structure from atomic-scale dislocations to micro-scale grain boundaries, causing zero-dimensional cavitation defects extending from the substrate 100 to evolve into high-dimensional defects. This reduces phonon scattering across multiple frequency bands, reduces carrier scattering, improves the thermal conductivity of the lattice, synergistically controls electron and phonon transport, improves the power factor of the laser system, obtains a thermoelectric figure of merit greater than 2.0, improves the hole transport efficiency in the active layer 103, improves the refractive index dispersion of the laser, and enhances the mode gain, power factor, and slope efficiency of the laser system, as shown in the table below.

[0038] Traditional lasers Laser in this embodiment range of change Slope efficiency (W / A) 0.8 1.8 125％ Optical power (W) 3.5 4.8 37％ Limiting factors 1.40％ 2.10％ 50％

[0039] More specifically, in this thermoelectric figure of merit control layer 107, the Si doping concentration ≥ H impurity concentration ≥ C impurity concentration. This is specifically manifested as follows:

[0040] The Si doping concentration of the thermoelectric figure control layer 107 is greater than 1E19cm. -3 ;

[0041] The C impurity concentration of thermoelectric figure control layer 107 is 1E15cm. -3 Up to 1E17cm -3 ;

[0042] The H impurity concentration in thermoelectric figure control layer 107 is 5E16cm⁻¹. -3 Up to 5E17cm -3 .

[0043] This embodiment, through specific control of the Si doping concentration, C impurity concentration, and H impurity concentration of the thermoelectric figure of merit control layer 107, can reduce phonon scattering, improve lattice thermal conductivity, reduce thermoelectric figure of merit, improve electrical transport characteristics, enhance optical confinement effect, limit and reduce the internal loss of the laser, reduce the room temperature threshold voltage of the laser, increase the slope efficiency to 1.5 W / A, and increase the continuous operating life at room temperature to 10,000 hours.

[0044] Furthermore, the thermoelectric figure of merit control layer 107 is any one or any combination of AlGaN, AlInGaN, GaN, AlInN, and InGaN, with a thickness of 10 to 50,000 angstroms.

[0045] Furthermore, the lower confinement layer 101, the lower waveguide layer 102, the upper waveguide layer 104, the electron blocking layer 105, and the upper confinement layer 106 include any one or any combination of GaN, AlGaN, InGaN, AlInGaN, AlN, InN, AlInN, SiC, Ga2O3, BN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, AlInAs, AlInP, AlGaP, and InGaP.

[0046] Furthermore, the active layer 103 is a periodic structure composed of a well layer and a barrier layer, with a period of m: 1 ≤ m ≤ 3; the well layer of the active layer 103 is any one or any combination of GaN, InGaN, InN, AlInN, AlInGaN, and AlGaN, with a thickness of p: 5 ≤ p ≤ 100 angstroms; the barrier layer of the active layer 103 is any one or any combination of GaN, InGaN, InN, AlInN, AlInGaN, and AlN, with a thickness of q: 10 ≤ q ≤ 200 angstroms.

[0047] Furthermore, the thickness of the lower waveguide layer 102 is x: 10 ≤ x ≤ 9000 angstroms; the thickness of the upper waveguide layer 104 is y: 10 ≤ y ≤ 9000 angstroms.

[0048] Furthermore, the thickness of the lower confinement layer 101 is z: 10 ≤ z ≤ 90000 angstroms; the thickness of the upper confinement layer 106 and the electron blocking layer 105 is n: 10 ≤ n ≤ 80000 angstroms.

[0049] Furthermore, the substrate 100 includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, sapphire / SiO2 composite substrate, sapphire / AlN composite substrate, and sapphire / SiN composite substrate. x Any one of the following composite substrates: magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2, and LiGaO2.

[0050] This embodiment constructs a multi-level structure from atomic-scale dislocations to microscale grain boundaries by setting a thermoelectric figure of merit control layer 107 between the substrate 100 and the lower confinement layer 101. This structure utilizes the interface concentration differences between the thermoelectric figure of merit control layer 107 and the substrate 100 and the lower confinement layer 101 regarding the Si doping concentration, H impurity concentration, and C impurity concentration. This allows zero-dimensional cavitation defects extending from the substrate 100 to evolve into high-dimensional defects, reducing phonon scattering across multiple frequency bands, reducing carrier scattering, improving the thermal conductivity of the lattice, synergistically controlling electron and phonon transport, improving hole transport efficiency in the active layer 103, improving the refractive index dispersion of the laser, and enhancing the mode gain, power factor, and slope efficiency of the laser system. The slope efficiency is improved by 125%, the optical power by 37%, and the confinement factor by 50%.

[0051] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A semiconductor laser with a thermoelectric figure of merit control layer, comprising, 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, characterized in that, A thermoelectric figure of merit control layer is disposed between the substrate and the lower confinement layer; the thermoelectric figure of merit control layer is any one or any combination of AlGaN, AlInGaN, GaN, AlInN, and InGaN, and has a thickness of 10 to 50,000 angstroms. The Si doping concentration of the thermoelectric figure of merit control layer is greater than that of the substrate and the lower confinement layer, respectively. The C impurity concentration of the thermoelectric figure of merit control layer is less than that of the lower confinement layer. The H impurity concentration of the thermoelectric figure of merit control layer is less than or equal to that of the lower confinement layer.

2. The semiconductor laser with a thermoelectric figure of merit control layer according to claim 1, characterized in that, In the thermoelectric figure of merit control layer, the Si doping concentration is ≥ H impurity concentration ≥ C impurity concentration.

3. The semiconductor laser with a thermoelectric figure of merit control layer according to claim 1, characterized in that, The Si doping concentration of the thermoelectric figure control layer is greater than 1E19cm⁻¹. -3 .

4. The semiconductor laser with a thermoelectric figure of merit control layer according to claim 1, characterized in that, The C impurity concentration of the thermoelectric figure control layer is 1E15cm⁻¹. -3 Up to 1E17cm -3 .

5. The semiconductor laser with a thermoelectric figure of merit control layer according to claim 1, characterized in that, The H impurity concentration of the thermoelectric figure control layer is 5E16cm⁻¹. -3 Up to 5E17cm -3 .

6. The semiconductor laser with a thermoelectric figure of merit control layer according to claim 1, characterized in that, The lower confinement layer, lower waveguide layer, upper waveguide layer, electron blocking layer, and upper confinement layer include GaN, AlGaN, InGaN, AlInGaN, AlN, InN, AlInN, SiC, and G. a2 Any one or any combination of O3, BN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, AlInAs, AlInP, AlGaP, and InGaP.

7. The semiconductor laser with a thermoelectric figure of merit control layer according to claim 1, characterized in that, The active layer is a periodic structure composed of a well layer and a barrier layer, with a period of m: 1≤m≤3; the well layer of the active layer is any one or any combination of GaN, InGaN, InN, AlInN, AlInGaN, and AlGaN, with a thickness of p: 5≤p≤100 angstroms; the barrier layer of the active layer is any one or any combination of GaN, InGaN, InN, AlInN, AlInGaN, and AlN, with a thickness of q: 10≤q≤200 angstroms.

8. The semiconductor laser with a thermoelectric figure of merit control layer according to claim 1, characterized in that, The thickness of the lower waveguide layer is x: 10 ≤ x ≤ 9000 angstroms; the thickness of the upper waveguide layer is y: 10 ≤ y ≤ 9000 angstroms; the thickness of the lower confinement layer is z: 10 ≤ z ≤ 90000 angstroms; and the thicknesses of the upper confinement layer and the electron blocking layer are both n: 10 ≤ n ≤ 80000 angstroms.

9. The semiconductor laser with a thermoelectric figure of merit control layer according to claim 1, characterized in that, The substrates include sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, InP, sapphire / SiO2 composite substrates, sapphire / AlN composite substrates, and sapphire / SiN composite substrates. x Any one of magnesium aluminum spinel, MgO, ZnO, ZrB2, LiAlO2 and LiGaO2.

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