Transient Behavior of Color Diodes

Abstract

AbstractAmorphous silicon (a-Si:H) based n-i-p-i-n/p-i-n-i-p structures serve as two color detectors. These basic structures can be extended to obtain multi color detection. In this paper capacitance measurements in the dark and under various illumination conditions as well as photo and bias current transient measurements in the time range 10-6-10-2 s are presented. The transients have been investigated for different bias voltages and photon fluxes.Device capacitance becomes strongly bias dependent if illumination is applied to the sensor. It is dominated by the reverse biased diode of the nipin/pinip structure. Bias and photocurrent transients are influenced by defect recharging due to injection. For high photon fluxes only defect states near the band edges contribute to the transient current. This behavior is confirmed by dispersion like transient phenomena. Under dark conditions deep defects influence the transient behavior.