It was noted that studies carried out on GaN devices showed that they had a high defect density in their band-gaps. These defects had a direct effect upon the electrical characteristics of the devices, by contributing leakage currents and trap-assisted tunnel currents. Numerical calculations were carried out here, based upon the experimental data, in order to study the contribution of each component of the current. A study was also made of the capacitance–frequency characteristics, which permitted the location of defects in the band-gap. The effect of the series resistance upon the current–voltage characteristics was considered, as well as the influence of defects upon the photo-detector response time and rejection ratio.

Impact of the Defects on the Electrical and Optical Properties of AlGaN Ultraviolet Photodetectors. M.Hanzaz, A.Bouhdada, P.Gibart, F.Omnès: Journal of Applied Physics, 2002, 92[1], 13-8