Conductivity control of GaN and fabrication of UV/blue GaN light emitting devices

Abstract

The development of the technology for heteroepitaxial growth of high-crystalline-quality GaN films on sapphire substrates using AlN buffer layers, the establishment of a technique for control of conductivity for n-type GaN by Si-doping, and the realization of p-type Mg-doped GaN using low-energy electron-beam irradiation treatment have enabled us to fabricate a high performance, short wavelength LED based on GaN. In this paper, we review the recent developments of AlGaN/GaN multi-layered structures showing quantum-size effects, and of LEDs with AlGaN/GaN double heterostructures which emit light in the blue to UV region with output power of more than a few milliwatts at room temperature.