Impacts of ammonia background flows on structural and photoluminescence properties of InN dots grown on GaN by flow-rate modulation epitaxy

Structural and photoluminescence (PL) properties of InN dots grown on GaN by metal organic vapor phase epitaxy using the flow-rate modulation technique, and their dependence on growth conditions, were investigated. An ammonia (N H3) background flow was intentionally supplied during indium deposition periods to control the kinetics of adatoms and hence the morphology of InN dots. Samples prepared under lower N H3 background flows generally exhibit narrower and more intense PL signals peaked at lower emission energies. The authors point out that the N H3 background flow is an important parameter that controls not only the nucleation process but also the emission property of InN dots.