Highly efficient light-emitting diode by using air to form patterned substrate and preparation method thereof

Abstract

The invention relates to a highly efficient light-emitting diode by using air to form a patterned substrate, which is characterized by sequentially comprising the substrate, a cavity formed by air arranged on the substrate, and the GaN-based light-emitting diode arranged above the cavity. The preparation method of the highly efficient light-emitting diode by using the air to form the patterned substrate comprises the following steps: 1) preparing a film layer with a high-melting-point material; 2) through lithography, etching on the substrate and preparing a pattern with the high-melting-point material; 3) preparing an epitaxial layer of the GaN-based light-emitting diode on the patterned substrate; 4) putting into an etching solution, and removing the high-melting-point material below the epitaxial layer of the GaN-based light-emitting diode through side etching, and forming the cavity; and 5) preparing an LED chip. The invention has the advantages that: the patterned substrate formed by air has higher reflectivity, and the whole process is relatively simple and easy to control, and is suitable for large-scale commercial production.

Description

technical field [0001] The invention relates to a high-efficiency light-emitting diode which uses air to form a pattern substrate and a preparation method thereof. Background technique [0002] GaN-based light-emitting diodes (LEDs) have been widely used in the fields of display technology and solid-state lighting due to their excellent characteristics such as long life, high reliability, high efficiency and energy saving. However, due to the large difference between the refractive index of the GaN light-emitting diode material (n=2.4) and the refractive index of the air (n=1.0), the critical angle of total reflection is only about 25 degrees, and most of the light generated by the light-emitting layer can only Totally reflected internally and cannot escape. In order to change this shortcoming, in the known technology, someone proposes to roughen the substrate to improve the light extraction efficiency. There are two main types of substrate roughening methods: [0003] 1. ...

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Problems solved by technology

Ordinary etching equipment cannot meet this requirement

Wet etching of sapphire also requires the use of phosphoric acid at high temperatures (greater than 200 degrees Celsius), and the uniformity of the pattern and the repeatability of the process are relatively poor

[0006] 2) The refractive index of sapphire is 1.8. When light enters the substrate from the epitaxial layer, the patterned sapphire can also improve the reflectivity and increase the front light extraction efficiency, but the improvement is limited

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