A method for improving the luminous performance of LEDs based on laser irradiation of gallium nitride epitaxial wafers

Abstract

The invention discloses a method for improving the light emitting property of an LED by using a laser radiated gallium nitride epitaxial wafer as the substrate of the LED, and belongs to the field of material preparation. The method comprises the following steps: firstly, pretreating the GaN epitaxial wafer (the surface of the epitaxial wafer is of a p type) so as to remove pollution attachment, organic residues and the like on the surface and reducing the lattice imperfection of the surface; radiating the GaN epitaxial wafer by using a 248nm excimer laser with the single pulse energy density of 0.15J / cm<2> to 0.6J / cm<2>, depositing a metal electrode on the surface of a sample according to a magnetron sputtering method, and further performing electric testing on metal semiconductor ohmic contact such as the carrier concentration and the surface resistivity, the testing result shows that various electric properties of the radiated sample are remarkably changed, and thus the ohmic contact of the radiated sample is greatly improved. The GaN epitaxial wafer before or after being radiated is manufactured by using a progress LED process, the LED characteristic parameters such as the positive voltage, the negative leakage current and the light emission power of the LED are tested, and the result shows that the LED characteristic parameters are all improved to different extents.

Description

technical field [0001] The invention belongs to the field of material preparation. Background technique [0002] Wide bandgap semiconductors represented by materials such as gallium nitride and silicon carbide are emerging materials with rich physical properties, and many of their electrical and optical properties far exceed those of the previous generation of semiconductor materials. Wide bandgap semiconductors are playing an increasingly important role in current production and life, especially gallium nitride materials play a pivotal role in the human lighting industry, and are widely used in the new generation of lighting LED devices. [0003] The bandgap of GaN material is direct bandgap type, and its bandgap width is 3.39eV at room temperature, which belongs to the category of wide bandgap semiconductors, and generally has a high quantum efficiency during carrier recombination. The GaN material has a direct band gap, which means that it has a wide band gap, and is ver...

AI Technical Summary

Problems solved by technology

At present, how to improve the luminous performance of GaN-based blue LEDs is one of the global academic hotspots. The reason is that the research on the luminescent materials of blue LEDs started late, and its material properties have not reached the expected level.

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