Narrow-width photoluminescence spectra of InGaN quantum wells grown on GaN (0001) substrates with misorientation toward [1 1^-00] direction

ABSTRACT The optical properties of InGaN quantum wells on misoriented GaN (0001) substrates were investigated. The suctuationof peak wavelength and full width at half maximum of micro-photoluminescence from InGaN quantum wells was largewhen the misorientation angle was 0.0 . The micro-photoluminescence showed narrow-width spectra, with full width athalf maximum below 60 meV, of InGaN quantum wells grown on GaN (0001) substrates with a misorientation angle ofaround0.28 toward[1 100] direction. These results indicate that InGaN quantumwells havehigh crystalline qualitywhenoInGaN quantumwells are grown with misorientation angle between 0.2 and 0.3 toward [1 100] direction.oKeywords: Micro-photoluminescence,InGaN, quantumwells, GaN substrates 1. INTRODUCTION GaN-basedlasershaveattractedmuchattentioninreg ardto epitaxialgrowthanddeviceapplications. 1,2 Theheteroepitaxyof GaN-based layers on sapphire or SiC s ubstrates deteriorates crystalline qua lity and device performance, due to dislo-cations and defects generated from the mismatch of lattice constant and thermal expansion coe cient. In contrast, thehomoepitaxyof GaN-based layerson GaN substrates is exp ectedto bring about superior crystalline quality and higher de-vice characteristics. Recently, large-areaGaN substrates were demonstrated