LED epitaxial layer growth method for improving luminous efficiency and LED epitaxial layer

Abstract

The invention provides an LED epitaxial layer growth method for improving luminous efficiency and an LED epitaxial layer. A P type hole injection layer comprises a first double-layer unit and a second double-layer unit. The first double-layer unit comprises a first AlGaN layer and a first GaN layer, the thickness of the first AlGaN layer and the first GaN layer ranges from 2 nm to 5 nm, the ratio of the first AlGaN layer to the first GaN layer in one period ranges from 1:1 to 3:1, and the period ranges from 5 to 10. The second double-layer unit comprises a second AlGaN layer and a second GaN layer, the thickness of the second AlGaN layer and the second GaN layer ranges from 2 nm to 5 nm, the ratio of the second AlGaN layer to the second GaN layer in one period ranges from 1:1 to 3:1, and the period ranges from 5 to 10. The P type hole injection layer is formed by a P type AlGaN / GaN superlattice layer which grows at a low temperature and a P type AlGaN / GaN superlattice layer which grows at a high temperature, the Droop effect of an LED chip under the high current density condition is effectively reduced, injection efficiency of charge curriers is improved, and luminous efficiency of devices is improved.

Description

technical field [0001] The invention relates to the technical field of LED epitaxial design, in particular to a method for growing an LED epitaxial layer with an improved P-type hole injection layer structure and the LED epitaxial layer. Background technique [0002] LEDs are widely used in a wide range of fields such as display screens, sensors, communications, and lighting. As the core semiconductor device, GaN-based blue LEDs can be combined with phosphors to produce white light, which is very attractive in terms of lighting. [0003] In the preparation of the GaN-based LED epitaxial layer, the characteristics of the P-type hole injection layer is an important factor affecting the electrical properties of the LED. The existing P-type GaN preparation technology has greatly increased the Mg doping concentration (up to E20 order of magnitude), but there is a phenomenon that the mobility is low when the doping concentration is too high. Moreover, too high doping of Mg will ...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a method for growing an LED epitaxial layer in which the P-type hole injection layer is composed of a P-type AlGaN / GaN superlattice layer grown at a low temperature and a P-type AlGaN / GaN superlattice layer grown at a high temperature LED epitaxial layer to solve the technical problems that the P-type electron blocking layer cannot effectively block some electrons from tunneling into the P-region to form carrier leakage and the traditional high-temperature P-type hole injection layer growth conditions cause damage to the MQW layer.

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