High-luminous efficiency light emitting diode epitaxial slice and preparation method thereof

Abstract

The invention discloses a high-luminous efficiency light emitting diode epitaxial slice and a preparation method thereof and belongs to the light-emitting diode field. The high-luminous efficiency light emitting diode epitaxial slice includes a substrate as well as a u type GaN layer, an n-type GaN layer, a multiple-quantum well active layer, a P-type AlGaN layer and a P-type GaN carrier layer which cover the substrate sequentially, wherein the multiple-quantum well active layer includes a plurality of InGaN well layers and a plurality of Gan barrier layers which grow alternately, and the P-type AlGaN layer includes a first P-type AlGaN sub layer, a u type GaN sub layer and a second P-type AlGaN sub layer which cover the multiple-quantum well active layer sequentially. According to the high-luminous efficiency light emitting diode epitaxial slice, potential energy required by holes in the P-type GaN carrier layer to climb over the P-type AlGaN layer can be decreased; quantum states can be formed in the u type GaN sub layer; holes in the P-type GaN carrier layer, of which the potential energy is lower than the potential energy for climbing over the P-type AlGaN layer, can tunnel the u type GaN sub layer through the quantum tunneling effect, and can be further transmitted into quantum wells, and therefore, hole concentration in the multiple-quantum well active layer can be improved.

Description

technical field [0001] The invention relates to the field of light emitting diodes (English Light Emitting Diode, referred to as LED), in particular to a high luminous efficiency light emitting diode epitaxial wafer and a preparation method thereof. Background technique [0002] LED is known as the most promising green lighting source in the 21st century because of its advantages such as high brightness, low heat, long life, non-toxicity, and recyclability. As the most important category of LEDs, GaN-based LEDs are widely used in many fields. The existing GaN-based LED epitaxial wafer mainly includes a substrate, a buffer layer, an N-type GaN layer, a multi-quantum well active layer, a P-type AlGaN layer, and a P-type GaN carrier layer. [0003] During the working process of GaN-based LEDs, the electrons generated in the N-type GaN layer and the holes generated in the P-type GaN carrier layer migrate to the multi-quantum well active layer under the action of an electric fie...

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Problems solved by technology

[0005] As the working current of GaN-based LEDs increases, the current density increases accordingly. In this high current density scenario, the electrons injected into the MQW active layer also increase, resulting in the failure of some electrons to interact with the holes. The multi-quantum well active layer recombines and migrates to the P-type GaN carrier layer, resulting in an increase in the degree of electron leakage, which makes the luminous efficiency of the LED chip decrease under the condition of high current density.

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