Effect of growth interruption on In-rich InGaN/GaN single quantum well structures

摘要

We successfully grew In-rich InGaN/GaN single quantum well structures by metal-organic chemical vapor deposition and confirmed their formation by optical and structural measurements. Relatively high growth temperature (730 ℃) for InGaN layer facilitated the formation of 2-dimensional quantum well structures, presumably due to high adatom mobility. As the growth interruption time increased, the PL emission efficiency from InGaN layer improved with peak position blue-shifted and the dislocation density decreased by one order of magnitude. The high resolution cross-sectional TEM images clearly showed that the In-rich InGaN layer thickness reduced from 2.5 nm (without GI) to about 1 nm (with 10 s GI) and the InGaN/GaN interface became very flat with 10 s GI. We suggest that decomposition and mass transport processes on InGaN during GI is responsible for these phenomena.