Anomalous temperature dependence of space-charge-limited currents and photoconductivity in amorphous silicon

Steady-state photoconductivity and transient photoconductivity in a-Si is generally interpreted in terms of an exponential density of gap states. These assumptions can be tested by examining the temperature dependence of space-charge-limited currents. In this paper it is shown that space-charge-limited currents cannot be understood within the framework of an exponential distribution of gap states.