Epitaxial structure capable of effectively reducing Droop effect of LED

Abstract

The invention discloses an epitaxial structure capable of effectively reducing the Droop effect of an LED. The epitaxial structure comprises a substrate, an undoped gallium nitride layer, an N-type gallium nitride layer, a multi-quantum well layer, an electron barrier layer and a P-type gallium nitride layer which are successively stacked from bottom to top, wherein the multi-quantum well layer is formed by alternatively superposing multiple barrier layers AlxGa(1-x)N and trap layers InyGa(1-y)N. According to the invention, gradual change AlGaN of Al components are taken as the barrier layers, the barrier height difference between the valence band of the electron barrier layer and the barrier layer close to the electronic barrier layer is effectively reduced, the injection efficiency of cavities is improved, at the same time, through increasing the barrier height differences between the traps and the barriers in a multi-quantum well, the binding effect on electrons is further enhanced, the electrons are effectively prevented from overflowing, the composite probability of the electrons and the cavities in the multi-quantum well is enhanced, and the luminescence efficiency of the LED is accordingly improved. Compared to the prior art, the epitaxial structure provided by the invention is relatively simple in structure and facilitates MOCVD growth. According to the invention, the epitaxial structure capable of effectively reducing the Droop effect of the LED can be widely applied to the field of LEDs.

Description

technical field [0001] The invention relates to the field of LEDs, in particular to an epitaxial structure that can effectively reduce the Droop effect of the LED. Background technique [0002] LED has been recognized as the new solid-state light source most likely to enter the field of general lighting, so it has become the focus of global attention in recent years. In recent years, the third-generation wide-bandgap semiconductor materials represented by SiC and GaN have received widespread attention and vigorous research. Especially III-V nitride semiconductor materials (AlN, GaN and InN) and their related alloys and heterojunctions have significant advantages in high-temperature, high-frequency, high-power electronic devices and short-wavelength optoelectronic devices, and in the near future Breakthrough progress has been made in several years of research and application. [0003] The growth of epitaxial structure is the key technology of LED chips, and multiple quantum...

AI Technical Summary

Problems solved by technology

Different from traditional semiconductor optoelectronic materials, the cause of the Droop effect of GaN-based LEDs is very complicated, and correspondingly, there is a lack of effective solutions

Traditional epitaxial structures such as figure 1 As shown, the last quantum barrier of the multi-quantum well layer in this structure is connected to the P-type AlGaN electron blocking layer. The electron blocking layer blocks the electron transmission and also blocks the hole injection, so the overall luminous efficiency of the light-emitting diode cannot be obtained. Significant improvement

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