Formation of N2 bubbles along grain boundaries in (ZnO)1−x(GaN)x: nanoscale STEM-EELS studies†
Abstract
Direct evidence of N2 formation after annealing of (ZnO)1−x(GaN)x alloys was revealed. N2 was trapped by VZn+Ga-clusters, forming faceted voids along grain boundaries. This study shows that N–N bonding is a competitive path for nitrogen after annealing, in addition to the increasing Ga–N bonds, indicating that N in O substitution sites (NO) is not a stable configuration.