Engineering V-shaped pits in InGaN layers grown by PA-MBE toward optimizing the active region of green LEDs

Surface morphology of thick InGaN with higher indium content, grown on GaN/sapphire templates using plasma-assisted molecular beam epitaxy (PA-MBE) under metal-rich growth condition, is investigated as a function of growth temperature and III-V ratio using atomic force microscopy. V-shaped pits on the InGaN surface are found to diminish with the decrease in growth temperature and remain unchanged with variation in III-V ratio, while exhibiting a significant impact on surface roughness, crystal quality, and optical properties. Fluctuation in density and depth of V-shaped pits is discussed, taking into account the low growth temperature of PA-MBE. (C) 2019 Optical Society of Americ