Markedly distinct growth characteristics of semipolar (112¯2) and (1¯1¯22¯) InGaN epitaxial layers

Abstract

We compare metalorganic vapor phase epitaxy of InGaN/GaN heterostructures on semipolar (112¯2) and (1¯1¯22¯) GaN bulk substrates. In incorporation efficiency is higher for (112¯2) InGaN, which enables higher temperature growth of InGaN and is beneficial for quality improvement. InGaN/GaN quantum wells (QWs) on (112¯2) show abrupt interfaces, but those on (1¯1¯22¯) tend to form three-dimensional nanofacets. Differences in growth temperature and structures of the (112¯2) and (1¯1¯22¯) QWs cause higher internal quantum efficiencies of the (112¯2) [(1¯1¯22¯)] QWs at shorter (longer) wavelengths.