Low frequency noise and ions diffusion in the CdTe bulk single crystals

Abstract

The effect of ions diffusion on time dependence of noise and polarization phenomena of CdTe bulk single crystals has been carried out. We evaluated the instability of the reverse current of the Schottky contact at the P-type CdTe and the Au interface by a model which considers the effects of deep acceptors. The results shows small detrapping time compared to the experimental measurements. We suggested the diffusion of ions in depletion region at the metal - semiconductor interface causes an additional reduction of the barrier and could be considered as another responsible mechanism for the polarization effect. The CdTe samples showed noise source with dominant 1/ ƒn noise at low frequency, while the parameter n increases with repeating the measurements, indicating that another noise source has to be taken in account. The barrier fluctuating due to the ion diffusion in the depletion region can to be the another noise source,