CN117791308A - Semiconductor laser - Google Patents
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- CN117791308A CN117791308A CN202311533223.XA CN202311533223A CN117791308A CN 117791308 A CN117791308 A CN 117791308A CN 202311533223 A CN202311533223 A CN 202311533223A CN 117791308 A CN117791308 A CN 117791308A
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- 239000004065 semiconductor Substances 0.000 title claims abstract description 37
- 238000009826 distribution Methods 0.000 claims abstract description 63
- 239000000758 substrate Substances 0.000 claims abstract description 45
- 230000007480 spreading Effects 0.000 claims abstract description 23
- 238000003892 spreading Methods 0.000 claims abstract description 23
- 238000012887 quadratic function Methods 0.000 claims abstract description 3
- 229910052594 sapphire Inorganic materials 0.000 claims description 12
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- 230000003247 decreasing effect Effects 0.000 claims description 11
- 239000002131 composite material Substances 0.000 claims description 10
- 230000004888 barrier function Effects 0.000 claims description 7
- 229910010093 LiAlO Inorganic materials 0.000 claims description 3
- 229910020068 MgAl Inorganic materials 0.000 claims description 3
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 3
- 230000000737 periodic effect Effects 0.000 claims description 3
- 229910052710 silicon Inorganic materials 0.000 claims description 3
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- 238000002347 injection Methods 0.000 description 5
- 239000007924 injection Substances 0.000 description 5
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Abstract
The invention discloses a semiconductor laser, 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, wherein a current expansion layer is arranged between the substrate and the lower limiting layer, the current expansion layer is any one or any combination of a plurality of GaN, alGaN, alInGaN, alInN, alN, and the thickness is 10-5000 angstroms; the Al element distribution of the current expansion layer has y=sinx/x 2 Is a third quadrant curve distribution of (2); the Si doping concentration distribution of the current expansion layer has quadratic function curve distribution, and the quadratic term coefficient is smaller than 0; the current spreading layer has a spike in Si doping concentration. The invention improves the current transverse and longitudinal expansion efficiency of the n-type semiconductor, reduces the bulk resistance and the contact resistance of the n-type semiconductor, and reduces the voltage of the laser from more than 8.0V to less than 5V.
Description
Technical Field
The invention relates to the technical field of semiconductor photoelectric devices, in particular to a semiconductor laser.
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 various classification modes, and mainly comprises solid, gas, liquid, semiconductor, dye and other types of lasers; 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,
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) Use of lasers current densities up to KA/cm 2 More than 2 orders of magnitude higher than nitride light emitting diodes, thereby causing stronger electron leakage, more severe auger recombination, stronger polarization effect, more severe electron-hole mismatch, resulting in more severe efficiency decay Droop effect;
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: the light emitting diode generates radiation composite luminescence by transferring electron holes to an active layer or a p-n junction under the action of external voltage, and the laser can perform lasing only when the lasing condition is satisfied, the inversion distribution of carriers in an active area is necessarily satisfied, the stimulated radiation oscillates back and forth in a resonant cavity, light is amplified by propagation in a gain medium, the gain is larger than loss when the threshold condition is satisfied, and finally laser is output.
The nitride semiconductor laser has the following problems:
1) The increase of the In component of the quantum well can generate fluctuation and strain of the In component, the gain spectrum of the laser is widened, and the peak gain is reduced; the In component of the quantum well is increased, the thermal stability is deteriorated, the high-temperature p-type semiconductor and the growth of the limiting layer can cause thermal degradation of the active layer, and the quality of the active layer and the interface quality are reduced; the internal defect density of the active layer is high, the intersolubility gap between InN and GaN is large, inN phase separation segregation, thermal degradation and non-ideal crystal quality are caused, so that the quality of a quantum well and the quality of an interface are non-ideal, and a non-radiative recombination center or optical catastrophe is increased.
2) The quantum well polarization electric field improves the problems of hole injection barrier, hole overflow 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 and the gain is uneven, 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;
3) The lattice mismatch and strain of the active layer are greatly induced to generate a strong voltage electric polarization effect, a strong QCSE quantum confinement Stark effect is generated, the band-gap of the laser is increased, hole injection is inhibited, the hole is more difficult to transport in a quantum well, the carrier injection is uneven, the gain is uneven, and the improvement of the laser electric lasing gain is limited.
Disclosure of Invention
The invention provides a semiconductor laser, which improves the current transverse and longitudinal expansion efficiency of an n-type semiconductor, reduces the bulk resistance and the contact resistance of the n-type semiconductor, and reduces the voltage of the laser from more than 8.0V to less than 5V.
The invention provides a semiconductor laser 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, wherein a current expansion layer is arranged between the substrate and the lower limiting layer, the current expansion layer is any one or any combination of GaN, alGaN, alInGaN, alInN, alN, and the thickness is 10-5000A m; the Al element distribution of the current expansion layer has y=sinx/x 2 Is a third quadrant curve distribution of (2); si doping of the current spreading layerThe concentration distribution has quadratic function curve distribution, and the quadratic coefficient is smaller than 0; the current expansion layer has peak of Si doping concentration of 1E 19-5E 20cm -3 。
Preferably, the Si doping concentration profile of the substrate has a profile with a function y=sin|x|; the Si doping concentration of the substrate ranges from 5E17cm to 1E19cm -3 。
Preferably, the C element distribution, the O element distribution and the H element distribution of the current spreading layer have a function y=arcotx curve distribution.
Preferably, the Al element distribution of the current expansion layer has a decreasing trend toward the substrate direction, and the decreasing angle is α: alpha is more than or equal to 45 and less than or equal to 90 degrees; the Si doping concentration distribution of the current expansion layer is in a descending trend towards the substrate direction, and the descending angle is beta: beta is more than or equal to 40 and less than or equal to 85 degrees; the H element of the current expansion layer is distributed towards the substrate direction in a descending trend, and the descending angle is gamma: gamma is more than or equal to 30 and less than or equal to 75 degrees; the O element distribution of the current expansion layer is in a descending trend towards the substrate direction, and the descending angle is theta: θ is more than or equal to 40 and less than or equal to 85 degrees; c element of the current expansion layer is distributed towards the substrate direction in a descending trend, and the descending angle is phi: phi is more than or equal to 40 and less than or equal to 90 degrees;
preferably, the angles of variation of the Al element distribution, the Si doping concentration distribution, the C element distribution, the O element distribution, and the H element distribution of the current spreading layer have the following relationship: gamma is less than or equal to theta is less than or equal to phi and less than or equal to beta is less than or equal to alpha.
Preferably, the distribution range of H element of the substrate is 1E 16-5E 17cm -3 The distribution range of O element is 1E 16-1E 17cm -3 The distribution range of the C element is 5E 15-1E 17cm -3 。
Preferably, the active layer is a periodic structure consisting of a well layer and a barrier layer, and the period number is 3-1; the well layer of the active layer is any one or any combination of InGaN, gaN, alInGaN, the thickness is 10-60 m, the barrier layer is any one or any combination of GaN, alGaN, alInGaN, alN, alInN, alN, and the thickness is 5-80 m;
preferably, the upper waveguide layer and the lower waveguide layer are any one or any combination of GaN, alGaN, alInGaN, inGaN, alN, and the thickness is 10-500 a.
Preferably, the lower and upper confinement layers are GaN, alGaN, inGaN, alInGaN, alN, inN, alInN, siC, ga 2 O 3 Any one or any combination of a plurality of BN, gaAs, gaP, inP, alGaAs, alInGaAs, alGaInP, inGaAs, alInAs, alInP, alGaP, inGaP.
Preferably, the substrate comprises sapphire, silicon, ge, siC, alN, gaN, gaAs, inP, sapphire/SiO 2 Composite substrate, sapphire/AlN composite substrate, sapphire/SiN x Magnesia-alumina spinel MgAl 2 O 4 、MgO、ZnO、ZrB 2 、LiAlO 2 And LiGaO 2 Any one of the composite substrates.
Compared with the prior art, the semiconductor laser provided by the embodiment of the invention has the beneficial effects that: the invention improves the current transverse and longitudinal expansion efficiency of the n-type semiconductor, reduces the bulk resistance and the contact resistance of the n-type semiconductor, and reduces the voltage of the laser from more than 8.0V to less than 5V.
Drawings
Fig. 1 is a schematic view of a semiconductor laser according to an embodiment of the present invention;
fig. 2 is a structural SIMS secondary ion mass spectrum of a semiconductor laser according to an embodiment of the present invention;
FIG. 3 is a structural SIMS secondary ion mass spectrum of a semiconductor laser according to an embodiment of the present invention;
reference numerals: 100: a substrate; 101: a lower confinement layer; 102: lower waveguide layer by layer; 103: an active layer; 104: upper waveguide layer, 105: upper confinement layer, 106: a current spreading layer.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In order to solve the above-described problems, a semiconductor laser according to an embodiment of the present application will be described and illustrated in detail by the following specific examples.
Referring to fig. 1-3, the semiconductor laser provided by the invention sequentially comprises a substrate 100, a lower limiting layer 101, a lower waveguide layer 102, an active layer 103, an upper waveguide layer 104 and an upper limiting layer 105 from bottom to top, wherein a current expansion layer 106 is arranged between the substrate 100 and the lower limiting layer 101, the current expansion layer 106 is any one or any combination of GaN, alGaN, alInGaN, alInN, alN, and the thickness is 10-5000 angstroms; the Al element distribution of the current spreading layer 106 has y=sinx/x 2 Is a third quadrant curve distribution of (2); the Si doping concentration distribution of the current spreading layer 106 has a quadratic curve distribution, and the quadratic coefficient is smaller than 0; the current spreading layer 106 has a peak of Si doping concentration of 1E 19-5E 20cm -3 . The C element distribution, the O element distribution and the H element distribution of the current spreading layer 106 have a function y=arcotx curve distribution, so that the current lateral and longitudinal spreading efficiency of the n-type semiconductor is improved, the bulk resistance and the contact resistance of the n-type semiconductor are reduced, and the voltage of the laser is reduced from 8.0V to below 5V. The Al element distribution of the current spreading layer 106 is in a decreasing trend toward the substrate 100, and the decreasing angle is α: alpha is more than or equal to 45 and less than or equal to 90 degrees; the Si doping concentration distribution of the current spreading layer 106 decreases toward the substrate 100, and the decreasing angle is β: beta is more than or equal to 40 and less than or equal to 85 degrees; the distribution of the H element in the current spreading layer 106 is in a downward trend toward the substrate 100, and the downward angle is γ: gamma is more than or equal to 30 and less than or equal to 75 degrees; the O element distribution of the current spreading layer 106 is in a decreasing trend toward the substrate 100, and the decreasing angle is θ: θ is more than or equal to 40 and less than or equal to 85 degrees; the C element distribution of the current spreading layer 106 is in a decreasing trend toward the substrate 100, and the decreasing angle is phi: phi is more than or equal to 40 and less than or equal to 90 degrees; the angles of change of the Al element distribution, si doping concentration distribution, C element distribution, O element distribution, and H element distribution of the current spreading layer 106 have the following relationship: gamma is less than or equal to theta is less than or equal to phi and less than or equal to beta is less than or equal to alpha.
The Si doping concentration of the substrate 100The degree distribution has a curve distribution of the function y=sin|x|; the Si doping concentration of the substrate 100 ranges from 5E17cm to 1E19cm -3 . The distribution range of H element of the substrate 100 is 1E 16-5E 17cm -3 The distribution range of O element is 1E 16-1E 17cm -3 The distribution range of the C element is 5E 15-1E 17cm -3 。
The active layer 103 is a periodic structure formed by a well layer and a barrier layer, and the period number is 3-1; the well layer of the active layer 103 is any one or any combination of InGaN, gaN, alInGaN, the thickness is 10-60 m, the barrier layer is any one or any combination of GaN, alGaN, alInGaN, alN, alInN, alN, and the thickness is 5-80 m;
the upper waveguide layer 104 and the lower waveguide layer 102 are any one or a combination of any two or more of GaN, alGaN, alInGaN, inGaN, alN, the thickness is 10-500 m, and the lower confinement layer 101 and the upper confinement layer 105 are GaN, alGaN, inGaN, alInGaN, alN, inN, alInN, siC, ga 2 O 3 Any one or any combination of BN, gaAs, gaP, inP, alGaAs, alInGaAs, alGaInP, inGaAs, alInAs, alInP, alGaP, inGaP, the substrate 100 comprises sapphire, silicon, ge, siC, alN, gaN, gaAs, inP, sapphire/SiO 2 Composite substrate, sapphire/AlN composite substrate, sapphire/SiN x Magnesia-alumina spinel MgAl 2 O 4 、MgO、ZnO、ZrB 2 、LiAlO 2 And LiGaO 2 Any one of the composite substrates.
The foregoing is merely a preferred embodiment of the present invention, and it should be noted that modifications and variations could be made by those skilled in the art without departing from the technical principles of the present invention, and such modifications and variations should also be regarded as being within the scope of the invention.
Claims (10)
1. A semiconductor laser comprises a substrate (100), a lower limiting layer (101), a lower waveguide layer (102), an active layer (103), an upper waveguide layer (104) and an upper limiting layer (105) from bottom to top, wherein an electric circuit is arranged between the substrate (100) and the lower limiting layer (101)A current spreading layer (106), wherein the current spreading layer (106) is any one or any combination of a plurality of GaN, alGaN, alInGaN, alInN, alN, and the thickness is 10-5000 Emi; the Al element distribution of the current spreading layer (106) has y=sinx/x 2 Is a third quadrant curve distribution of (2); the Si doping concentration distribution of the current expansion layer (106) has quadratic function curve distribution, and the quadratic term coefficient is smaller than 0; the current spreading layer (106) has a peak of Si doping concentration of 1E 19-5E 20cm -3 。
2. A semiconductor laser according to claim 1, characterized in that the Si doping concentration profile of the substrate (100) has a profile of the function y = sin|x|; the Si doping concentration of the substrate (100) ranges from 5E17cm to 1E19cm -3 。
3. A semiconductor laser according to claim 1, characterized in that the C-, O-and H-element distributions of the current spreading layer (106) have a function y = arcotx curve distribution.
4. A semiconductor laser according to claim 1, characterized in that the Al element distribution of the current spreading layer (106) has a decreasing trend in the direction of the substrate (100), the decreasing angle being α: alpha is more than or equal to 45 and less than or equal to 90 degrees; the Si doping concentration distribution of the current expansion layer (106) is in a descending trend towards the direction of the substrate (100), and the descending angle is beta: beta is more than or equal to 40 and less than or equal to 85 degrees; the H element of the current expansion layer (106) is distributed towards the direction of the substrate (100) in a descending trend, and the descending angle is gamma: gamma is more than or equal to 30 and less than or equal to 75 degrees; o element of the current expansion layer (106) is distributed towards the direction of the substrate (100) in a descending trend, and the descending angle is theta: θ is more than or equal to 40 and less than or equal to 85 degrees; c element of the current expansion layer (106) is distributed towards the direction of the substrate (100) in a descending trend, and the descending angle is phi: phi is more than or equal to 40 and less than or equal to 90 degrees.
5. A semiconductor laser according to claim 4, characterized in that the angles of variation of the Al element distribution, si doping concentration distribution, C element distribution, O element distribution, H element distribution of the current spreading layer (106) have the following relationship: gamma is less than or equal to theta is less than or equal to phi and less than or equal to beta is less than or equal to alpha.
6. A semiconductor laser according to claim 1, characterized in that the substrate (100) has an H element distribution in the range of 1E 16-5E 17cm -3 The distribution range of O element is 1E 16-1E 17cm -3 The distribution range of the C element is 5E 15-1E 17cm -3 。
7. The semiconductor laser according to claim 1, wherein the active layer (103) has a periodic structure composed of a well layer and a barrier layer, and the number of periods is 3-1; the well layer of the active layer (103) is any one or any combination of InGaN, gaN, alInGaN, the thickness is 10-60 m, the barrier layer is any one or any combination of GaN, alGaN, alInGaN, alN, alInN, alN, and the thickness is 5-80 m.
8. A semiconductor laser according to claim 1, characterized in that the upper waveguide layer (104) and the lower waveguide layer (102) are each any one or a combination of any several of GaN, alGaN, alInGaN, inGaN, alN, and have a thickness of 10 to 500 a.
9. A semiconductor laser as claimed in claim 1, wherein the lower confinement layer (101) and the upper confinement layer (105) are each GaN, alGaN, inGaN, alInGaN, alN, inN, alInN, siC, ga 2 O 3 Any one or any combination of a plurality of BN, gaAs, gaP, inP, alGaAs, alInGaAs, alGaInP, inGaAs, alInAs, alInP, alGaP, inGaP.
10. A semiconductor laser according to claim 1, characterized in that the substrate (100) comprises sapphire, silicon, ge, siC, alN, gaN, gaAs, inP, sapphire/SiO 2 Composite substrate, sapphire/AlN composite substrate, sapphire/SiN x Magnesia-alumina spinel MgAl 2 O 4 、MgO、ZnO、ZrB 2 、LiAlO 2 And LiGaO 2 Any one of the composite substrates.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311533223.XA CN117791308A (en) | 2023-11-17 | 2023-11-17 | Semiconductor laser |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311533223.XA CN117791308A (en) | 2023-11-17 | 2023-11-17 | Semiconductor laser |
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| CN117791308A true CN117791308A (en) | 2024-03-29 |
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| CN202311533223.XA Pending CN117791308A (en) | 2023-11-17 | 2023-11-17 | Semiconductor laser |
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