Evidence of Carrier Localization in AlGaN/GaN‐Based UV Multiple Quantum Wells with Opposite Polarity Domains Provided by Nanoscale Imaging

Abstract

AlGaN‐based multiple quantum wells (MQWs) incorporating opposite polarity domains are grown by metal–organic chemical vapor deposition (MOCVD). A direct demonstration of the carrier localization effect is provided by a combination analysis of space‐resolved luminescence peak position and Ga/Al composition distribution. Furthermore, through Raman spectroscopy, it is found that compressive strain plays a key role in improving the optical properties of UV‐MQWs despite the inferior crystalline quality in the N‐polar domains. This suggests that incorporating sub‐micrometer‐scale polarity domains in the MQWs is promising for the development of efficient UV emitters.