GaN Surface Quantum Well In AlGaN∕GaN Transistor Heterostructure Studied By Contactless Electroreflectance

Abstract

Abstract. Contactless electroreflectance (CER) has been applied to study optical transitions in GaN capped AlGaN/GaN transistor heterostructure. In addition to strong AlGaN-related resonance, a clear CER resonance has been observed at the energy of 3.68 eV. This resonance has been attributed to the optical transition within the GaN cap layer which creates a surface quantum well (QW). The confinement energy and the electron-hole overlap integral for the surface QW have been calculated within the electron effective mass approximation. A good agreement between experimental data and theoretical calculations have been found.