Band bowing and Si donor levels in InGaN layers investigated by surface photo voltage spectroscopy

Abstract

Bowing parameter and intra gap states have been measured on good quality undoped and n-type Si doped InGaN layers, by surface photovoltage spectroscopy (SPS). Bowing parameter calculations have been done with consideration of strain and relaxed nature of InGaN layers. Si donor levels have been measured by SPS on layers with different indium content. Free carrier concentration and Si donor level variations as a function of In content have been analysed. It has been found that the interaction between In and Si plays a fundamental role in Si doping process in InGaN.