Gallium nitride-based light-emitting diode and its preparation method

Abstract

The present invention belongs to the field of optoelectronic device preparation. A high luminous efficiency gallium nitride-based light emitting diode (LED) and a preparation method therefor, wherein the LED may maintain a relatively high photoelectric conversion efficiency when a large electrical current is introduced, thereby mitigating the droop effect. The specific structure of the LED comprises two sections, wherein one section is a bottom layer and a light emitting layer (104) which are grown by using MOCVD technology, and the other section is a P-type layer grown by using molecular beam epitaxy technology; that is, a gallium-polar buffer layer (101), a non-doped nitride layer (102), an N-type nitride layer (103) and a multi-quantum-well luminescent layer (104) are grown on a sample by using MOCVD technology; the sample is then transferred into a molecular beam epitaxial apparatus reaction chamber for growing a nitrogen-polar electron barrier layer (205), a P-type nitride layer (206) and a P-type nitride contact layer (207). The preparation method may reduce the energy band bending caused by polarization between the electron barrier layer (205) and the multi-quantum-well luminescent layer (104), not only increasing the barrier height for electrons overshooting to a P-type layer, but also reducing the barrier for hole injection into the multi-quantum-well region.

Description

technical field [0001] The invention relates to the field of semiconductor optoelectronic device preparation, in particular to a preparation technology of gallium nitride-based LED with high light efficiency. Background technique [0002] The rapid development of wide bandgap III-V semiconductor materials has enabled the commercialization of high-brightness light-emitting diodes from green to near-ultraviolet. However, most of the current commercial LEDs are prepared by growing 001-plane nitrides on sapphire, silicon carbide or silicon substrates by MOCVD technology, and the surfaces are gallium polar planes. [0003] figure 1 A structure diagram of a conventional commercial gallium polar gallium nitride-based LED is shown, in which there is a strong polarization field between the multi-quantum well light-emitting layer 104 and the electron blocking layer 105 due to the difference in lattice constant. figure 2 It shows the energy band structure diagram of conventional com...

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Problems solved by technology

figure 2 It shows the energy band structure diagram of conventional commercial gallium polar gallium nitride-based LEDs. The electron blocking layer 104 generates positive charges at the interface due to tensile strain, causing the energy band to bend downward, so that the effective potential of the electron blocking layer in the conduction band is The barrier height is reduced, and the effective potential barrier in the valence band is increased, which not only reduces the electron blocking ability of the electron blocking layer, but also increases the potential barrier for holes injected into the multi-quantum well light-emitting layer on the p-type side.

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