Correlation of Thermal with Structural and Optical Properties of High Quality GaN/Sapphire (0001) Grown by Metalorganic Chemical Vapor Deposition

Authors compare three unintentionally doped GaN samples, grown in an EMCORE commercial reactor by MOCVD on sapphire (0001), with the growth parameters optimized in order to improve the crystalline quality. A direct correlation between higher thermal conductivity values and increasing low temperature (77 K) ratio of the near band edge/deep level photoluminescence signals, decreasing surface roughness and dislocation density, and narrowing of the FWHM from XRD scans was established indicating the importance of growth optimization. The implications of these results for optoelectronic applications is discussed. 16 refs.