Photoconductivity Studies of Al0.18Ga0.82N/GaN Single Heterostructure

Abstract

We present spectral photoconductivity (SPC) and transient photoconductivity (TPC) studies in a Al 0.18 Ga 0.82 N/GaN single heterostructure. We attribute near bandgap peaks in the SPC between 300 and 500 K to a deep trap-conduction band transition. The trap distribution lies approximately 100 meV above the valence band edge, for both GaN and AlGaN layers. In TPC studies we show that charge buildup after strong pulsed laser excitation can be detected by anomalous photocurrent decay.