Recent Progress in GaN-Based Superlattices for Near-Infrared Intersubband Transitions

A review of the recent progress in intersubband transitions in GaN-based superlattice structures grown by plasma-assisted molecular beam epitaxy (MBE) is presented. Careful control of the growth parameters resulted in reduced threading dislocation density as well as optimized interfaces for the superlattices. Intersubband absorption has been observed from a variety of configurations involving GaN single or asymmetric double quantum wells with either thick Al sub x Ga sub 1-x N barriers or short-period GaN/Al sub x G sub 1-x N superlattice barriers.