Misoriented grains with a preferential orientation in a-plane oriented GaN layers

► GaN layers grown on r-plane sapphire were investigated using transmission electron microscopy. ► The predominant structure was a-plane oriented single-crystal. Misoriented grains with a preferential orientation were included. ► Orientation relationship between the a-plane layers and the misoriented grains revealed. ► Orientation relationship analyzed using atomic structure models.