A semiconductor light emitting element

Abstract

The present invention relates to the technical field of semiconductor optoelectronic devices, and in particular to a semiconductor light-emitting element, which comprises, from bottom to top, a substrate, a first conductive semiconductor, a multi-quantum well, a conductive hole injection layer, and a second conductive semiconductor, wherein the H concentration of the conductive hole injection layer is 5E18-1E20cm ‑3 , O concentration is 1E17~5E18cm ‑3 By setting a conductive hole injection layer and controlling its C / H / O content ratio, the barrier height of electrons can be increased and the barrier height of holes can be reduced, effectively blocking electron overflow and improving the efficiency of hole injection into multiple quantum wells, thereby improving the radiation recombination efficiency of semiconductor light-emitting elements.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor optoelectronic devices, and in particular to a semiconductor light-emitting element. Background Art

[0002] Semiconductor light-emitting elements have a wide range of adjustable wavelengths, high luminous efficiency, energy saving and environmental protection, long life of more than 100,000 hours, small size, strong designability and other factors. They have gradually replaced incandescent lamps and fluorescent lamps, and have become the light source for ordinary household lighting. They are also widely used in new scenarios, such as indoor high-resolution display screens, outdoor display screens, mobile TV backlighting, street lights, car lights, flashlights and other application fields. However, traditional nitride semiconductors are grown on sapphire substrates, with large lattice mismatch and thermal mismatch, resulting in high defect density and polarization effect, reducing the luminous efficiency of semiconductor light-emitting elements; at the same time, the hole ionization efficiency of traditional nitride semiconductors is much lower than the electron ionization efficiency, resulting in a hole concentration that is more than one order of magnitude lower than the electron concentration. Excess electrons will overflow from the multi-quantum well to the second conductive semiconductor to produce non-radiative recombination. The low hole ionization efficiency will make it difficult for the holes of the second conductive semiconductor to be effectively injected into the multi-quantum well, resulting in low luminous efficiency of the multi-quantum well. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a semiconductor light-emitting element, which increases the barrier height of electrons and reduces the barrier height of holes by setting a conductive hole injection layer and controlling the C / H / O content ratio, effectively blocks electron overflow, and improves the efficiency of hole injection into multiple quantum wells, thereby improving the radiation recombination efficiency of the semiconductor light-emitting element.

[0004] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0005] The present invention provides a semiconductor light-emitting element, which comprises, from bottom to top, a substrate, a first conductive semiconductor, a multi-quantum well, a conductive hole injection layer, and a second conductive semiconductor, wherein the H concentration of the conductive hole injection layer is 5E18-1E20cm -3 , C concentration is 1E17~5E18cm -3 , O concentration is 1E17~5E18cm -3 .

[0006] In a possible technical solution, the H concentration of the first conductive semiconductor is 1E17-1E18 cm -3 , C concentration is 1E16~5E17cm -3 , O concentration is 1E16~5E17cm -3 .

[0007] In a possible technical solution, the H concentration of the multi-quantum well is 1E17-1E18cm -3 , C concentration is 1E16~5E17cm -3 , O concentration is 1E16~1E18cm -3 .

[0008] In a possible technical solution, the H concentration of the second conductive semiconductor is 1E18-5E21cm -3 , C concentration is 1E17~5E21cm -3 , O concentration is 1E17~5E21cm -3 .

[0009] In a possible technical solution, the Mg doping concentration of the conductive hole injection layer is greater than 1E19 cm -3 .

[0010] In a possible technical solution, the Mg doping concentration of the second conductive semiconductor is greater than 1E18 cm -3 .

[0011] In a possible technical solution, the materials of the first conductive semiconductor, the second conductive semiconductor, and the multi-quantum well are Al x I n y Ga 1-x-y N material, wherein the Al component x is 0-40%, and y is 0-80%; the light emitted by the multi-quantum well is in the range of 350-600nm from the ultraviolet band to the yellow light band.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: by providing a conductive hole injection layer and controlling its C / H / O content ratio, the barrier height of electrons is increased and the barrier height of holes is reduced, thereby effectively blocking electron overflow and improving the efficiency of hole injection into multiple quantum wells, thereby improving the radiation recombination efficiency of semiconductor light-emitting elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic structural diagram of a semiconductor light emitting element according to an embodiment of the present invention;

[0014] Figure 2 is a SIMS secondary ion mass spectrum of a semiconductor light emitting element according to an embodiment of the present invention;

[0015] Reference numerals: 100: substrate; 101: first conductivity type semiconductor; 102: multiple quantum well; 103: conductivity type hole injection layer; 104: second conductivity type semiconductor. DETAILED DESCRIPTION

[0016] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0017] like Figure 1 As shown, the semiconductor light emitting element of the first embodiment of the present invention comprises, from bottom to top, a substrate 100, a first conductive semiconductor 101, a multi-quantum well 102, a conductive hole injection layer 103, and a second conductive semiconductor 104. The substrate 100 is a substrate on which nitride semiconductor crystals can be epitaxially grown, and a substrate having a high transmittance (for example, the transmittance of the light is above 50%) for the wavelength range of light emitted by the semiconductor light emitting element can be selected and used; for example, aluminum nitride, sapphire, GaN, etc. can be listed as the material of the substrate 100; the first conductive semiconductor 101 is a substrate on which a nitride semiconductor crystal can be epitaxially grown, and a substrate having a high transmittance (for example, the transmittance of the light is above 50%) for light emitted by the semiconductor light emitting element can be selected and used; for example, aluminum nitride, sapphire, GaN, etc. can be listed ... can be selected and used; for example, aluminum nitride, sapphire, GaN, etc. can be listed; the first conductive semiconductor 101 is a substrate on which a nitride semiconductor crystal can be epitaxially grown, and a substrate having a high transmittance (for example, the transmittance of the light is above 50%) can be selected and used; for example, aluminum nitride, sapp The first conductive semiconductor 100 and the second conductive semiconductor 104 can be an n-type semiconductor layer with an n-type conductivity; or a p-type semiconductor layer with a p-type conductivity; the first conductive semiconductor, the multiple quantum well, the conductive hole injection layer and the second conductive semiconductor are sequentially stacked on the substrate 100, and the stacked semiconductor layers are stacked by organic metal chemical vapor deposition (MOCVD), organic metal vapor phase epitaxy (MOVPE), molecular beam epitaxy (MBE) and hydride vapor phase epitaxy (HVPE) methods; the H concentration of the conductive hole injection layer is 5E18-1E20cm -3 , C concentration is 1E17~5E18cm -3 , O concentration is 1E17~5E18cm -3 , by controlling the pressure, temperature, MO source, flow rate and ratio of N2 / H2 / NH3 during the stacking process, the H / O content is regulated, the barrier height of electrons is increased and the barrier height of holes is reduced, the electron overflow is effectively blocked, and the efficiency of hole injection into multiple quantum wells is improved. Due to the improvement of the hole expansion ability, the luminescence uniformity is improved, thereby improving the radiation recombination efficiency of semiconductor light-emitting elements;.

[0018] As an improvement to the above technical solution, the H concentration of the first conductive semiconductor is 1E17-1E18 cm -3 , C concentration is 1E16~5E17cm -3 , O concentration is 1E16~5E17cm -3 By controlling the optimal C / H / O content ratio and ratio concentration suitable for the first conductive type semiconductor, the lateral growth ability of the first conductive type semiconductor is improved, the semiconductor merger is promoted, the surface of the flat atomic-level steps is obtained, the extension of the underlying dislocation is blocked, the surface black spots are improved, the crystal quality of the first conductive type semiconductor is improved and the defect density is reduced. The defect density of the tested first conductive type semiconductor is less than 5E18cm -2The half-height widths of the crystal plane (002) and the plane (102) tested by XRD are less than 180 / 200 arc seconds respectively; at the same time, the electron ionization efficiency of the first conductive semiconductor is improved, the electron ionization energy is reduced, the contact resistance of the semiconductor light-emitting element and the lateral expansion capacity of the current are reduced, so that the local current density is improved, the probability of local breakdown is reduced, and the ESD resistance is improved.

[0019] The multi-quantum well 102 is composed of a stacked structure formed by alternating well layers and barrier layers. Preferably, the H concentration of the multi-quantum well is 1E17-1E18 cm -3 , C concentration is 1E16~5E17cm -3 , O concentration is 1E16~1E18cm -3 , control the H / O concentration of the multi-quantum well within the specified range, reduce the non-radiative recombination centers of the multi-quantum well, enhance the quantum localization effect of the multi-quantum well layer, increase the overlap probability of the electron and hole wave functions, and improve the luminescence efficiency;

[0020] As an improvement to the above technical solution, the H concentration of the second conductive semiconductor is 1E18-5E21cm -3 , C concentration is 1E17~5E21cm -3 , O concentration is 1E17~5E21cm -3 Furthermore, the Mg doping concentration of the second conductive semiconductor is greater than 1E18 cm -3 By controlling the C / H / O concentration of the second conductive semiconductor and matching it with the Mg doping concentration, the hole ionization efficiency and Mg solubility can be improved, the lateral growth rate can be increased to make the surface of the second conductive semiconductor grow smoothly, and the lateral expansion ability and ESD resistance of holes can be improved.

[0021] As an improvement to the above technical solution, the Mg doping concentration of the conductive hole injection layer is greater than 1E19 cm -3 , controlling the doping concentration of the conductive hole injection layer helps to improve the hole concentration and mobility after doping.

[0022] As an improvement of the above technical solution, the materials of the first conductive semiconductor, the second conductive semiconductor, and the multi-quantum well are Al x In y Ga 1-x-y N material, wherein the Al component x is 0-40%, and y is 0-80%; the light emitted by the multi-quantum well is in the range of 350-600nm from the ultraviolet band to the yellow light band.

[0023] Figure 2This is a SIMS secondary ion mass spectrum of a semiconductor light-emitting element according to one specific embodiment of the present invention. The contents of elements such as C / H / O / Mg / Si / Al / Ga in each layer are all within the required range.

[0024] 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 light emitting element, characterized in that: From bottom to top, it includes a substrate, a first conductive semiconductor, a multi-quantum well, a conductive hole injection layer, and a second conductive semiconductor. The H concentration of the conductive hole injection layer is 5E18-1E20cm -3 , C concentration is 1E17~5E18cm -3 , O concentration is 1E17~5E18cm -3 , the H concentration of the first conductive semiconductor is 1E17~1E18cm -3 , C concentration is 1E16~5E17cm -3 , O concentration is 1E16~5E17cm -3 The H concentration of the multi-quantum well is 1E17-1E18cm -3 , C concentration is 1E16~5E17cm -3 , O concentration is 1E16~1E18cm -3 , the H concentration of the second conductive semiconductor is 1E18~5E21cm -3 , C concentration is 1E17~5E21cm -3 , O concentration is 1E17~5E21cm -3 The materials of the first conductive semiconductor, the second conductive semiconductor, and the multi-quantum well are Al x In y Ga 1-x-y N material, wherein the Al component x is 0-40%, and y is 0-80%; the light emitted by the multi-quantum well is in the range of 350-600nm from the ultraviolet band to the yellow light band.

2. The semiconductor light emitting element according to claim 1, wherein The Mg doping concentration of the conductive hole injection layer is greater than 1E19 cm -3 .

3. The semiconductor light emitting element according to claim 1, wherein: The Mg doping concentration of the second conductive semiconductor is greater than 1E18 cm -3 .

4. The semiconductor light emitting element according to claim 1, wherein: By controlling the H / O content ratio of the conductive hole injection layer, the barrier height of electrons is increased and the barrier height of holes is reduced, electron overflow is effectively blocked, and the efficiency of hole injection into the multi-quantum well is increased, thereby improving the radiation recombination efficiency of the semiconductor light-emitting element.

5. The semiconductor light emitting element according to claim 1, wherein: Control the H / O content of the first conductive semiconductor within a specified range, increase the two-dimensional growth rate, promote semiconductor merging, obtain a flat atomic-level step surface, and obtain a high carrier concentration greater than 5E18cm -3 A first conductivity type semiconductor.

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