Analysis of the transient leakage current of an a-Si : H P-I-N diode

Abstract

When a-Si:H p-i-n diodes are used for radiation detection for medical imaging, the leakage current is a sensitive characteristic of diode performance, and the transient current behavior may limit the sensitivity and stability of the p-i-n diode. Because of defect states within the band gap, the leakage current shows transient behavior. We investigate this behavior by introducing a time-dependent electric field, which originates from the variation of the ionized dangling bond density due to trapped charge emission. We assume the components of the leakage current to be the thermal generation current and the injection current at the p-i interface. The transient leakage current was calculated using this analytical model and was compared with the experimental results.