Effects of an in-situ SiNx interlayer on structural and optical properties for nonpolar a-plane GaN epilayers

Abstract

The structural and optical properties for a nonpolar GaN epilayer grown with an in situ SiNx interlayer was studied intensively. The superficial defects were decreased by 83% and root-mean-square was reduced by 61% for nonpolar GaN with an SiNx interlayer. The in situ SiNx was revealed to be powerful to block basal-plane stacking faults (BSFs) in nonpolar GaN because BSF density was reduced from 1.83 × 105 to 8.13 × 104 cm−1 and BSF-related emission was remarkably suppressed by the SiNx interlayer. Moreover, the fast decay lifetime increased from 16.2 to 71.1 ps, which implied the non-radiative recombination in nonpolar GaN was significantly suppressed after the insertion of the SiNx layer.