More Insight into the Transient Photocurrent Response of Three-Color Detectors

Nipiin structures with controlled bandgap and mobility-life-time product exhibit excellent stationary properties. However, the photocurrent transients of these devices show reasonable delay times in the range of tens of milliseconds before reaching steady state. Hence, the transient behavior after light switching of three color detectors based on a nipiin structure was studied by a detailed analysis of experimentally determined and simulated data. The numerical simulation reproduces well the characteristic features. The delayed current onset and the sign reversal of the transient photocurrent response are explained by trapping of holes in the vicinity of the central p-layer.