Electrical noise measurements in intrinsic amorphous silicon

Abstract

Abstract Noise measurements were performed on intrinsic glow-discharge a-Si: H. The noise is found to exhibit a l/f n dependence with 0.7 <n< 1·1. The theory of noise in a-Si: H is developed on the basis of random emission of electrons from the gap states into the conduction band and the experimental results are interpreted on this basis. It is shown that an activated conductivity mobility, with a fixed activation energy, is necessary to account for the temperature dependence of noise. This activation energy is shown to be determined by the mean thermalization time of excess carriers and the model is used to derive a value for the conductivity mobility μc at room temperature of 4·24cm2 V−1 s−1.