Method for improving light extraction efficiency of LED by using nanoscale ZnO

Abstract

The invention relates to a method for improving the light extraction efficiency of an LED by using nanoscale ZnO, belonging to the technical field of LEDs. The method comprises the following steps of: adding zinc oxide to diluted hydrochloric acid to form a saturated solution, then adding an H2O2 solution to the saturated solution, adding into a 40-DEG C constant-temperature water bath, putting an LED chip, with the light emergent surface facing upwards, into a reaction solution, and obtaining a nanoscale ZnO coarsened LED chip after 0.5-1h; and photoetching to form electrode patterns to finish the process of sputtering a P electrode. The method disclosed by the invention can be used for carrying out nanoscale ZnO deposition on a window layer of the LED so as to realize surface coarsening, thereby achieving the purpose of improving the light extraction efficiency of the LED.

Description

technical field [0001] The invention belongs to the technical field of LEDs, in particular to a surface roughening method for enhancing the light extraction efficiency of a light emitting diode (LED: Light Emitting Diode). Background technique [0002] Semiconductor LEDs have become a new generation of lighting sources in the 21st century due to their high electro-optic conversion efficiency, long life, and environmental protection. With the maturity of III-V semiconductor technology, the development of LED devices continues to develop in the direction of high efficiency and high brightness. [0003] Thanks to the introduction of epitaxial growth technology MOCVD and multi-quantum well structure (MQW), the internal quantum efficiency (quantum efficiency) of LED can be greater than 90%, or even close to 100%, and there is little room for improvement. However, since the semiconductor material usually has a high dielectric coefficient, the light generated in the active layer c...

AI Technical Summary

Problems solved by technology

First, photolithography technology can be used for nano-roughening, but due to the limitation of resolution, it is difficult to prepare nano-patterned substrates by traditional photolithography technology, and advanced photolithography technology with extremely high resolution, such as electron beam photolithography Lithography and extreme ultraviolet lithography, nano-roughening, high production cost

Second, the patent publication No. CN 101373714A discloses a method for preparing a nanoscale pattern substrate using metal self-assembly technology, but it requires multi-step processes such as deposition of silicon oxide, deposition of metal, and high-temperature nitrogen annealing. Complicated, in addition, the high temperature annealing process will also have an adverse effect on the quality of the LED epitaxial layer

Third, nanoscale hard masks can be prepared by spin-coating nanoparticles, and then roughened with thin film materials, but these materials themselves may pollute the LED production line

Fourth, the patent with the publication number CN101976712A discloses a method of using plasma etching to form nano-sized glue dots and using the glue dots as a mask to etch the film to be roughened, but the etching process will cause surface state and other defects. influences

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