Determination of Density of Localized States in a-Si:H from the Time Relaxation of Space-Charge-Limited Conductivity

Abstract

A new technique is described, which is suitable for the evaluation of the bulk density of localized states in undoped a-Si:H from the time relaxation of the conductivity limited by the space charge prepared by a previous injection of electrons. Time relaxations of the conductivity were measured for different values of bias applied across an n+–i–n+ device with thick undoped layer. The density of states determined from the measured data was compared with that extracted from the steady-state space-charge-limited current (SCLC) characteristics.