Thermally stimulated currents in CdTe polycrystalline films

Abstract

Investigations of trapping centers have been carried out in CdTe polycrystalline films by using the thermally stimulated conductivity (TX) technique. The measurements were performed in the temperature range from 80 to 300 K. The TSC spectra showed three peaks related to three trapping levels with energy activations of 0.18, 0.29, and 0.32 eV, respectively. The two first trapping levels correspond to known acceptor centers in bulk CdTe previously reported. It is suggested that the level at 0.32 eV is due to grain boundary defects characteristic of the polycrystalline films. The main parameters of these trapping centers have been determined by using known theoretical relations. The' temperature dependence of the dark resistivity indicates that the impurity conduction does not make an important contribution to the TSC spectra of the films. From these measurements an activation energy of 0.49 eV for the conductivity of the films was found. 0 1995 American Institute of Physics.

Diffusion-Controlled Electrodeposition and Characteristics of CdTe Films

“…The result of calculation gives m BE am 0 0X216f where m 0 is the free electron mass. If m BE is the same as the effective mass for holes, m h , then for f 3, m h am 0 0X65 which is in agreement with the adopted value of 0.64 [27]. This approach has also been used in estimating the number of bound electrons per molecule participating in dispersion in SnO 2 [26].…”

Influence of substrate temperature on the processing of CdTe and CdS thin films

“…A recent study using thermally stimulated conductivity has also indicated the presence of three trapping levels in CdTe with activation energies 0.18, 0.29 and 0.32 eV. The first two peaks were, however, found to correspond to two acceptor centres, while the third peak was attributed to grain boundary defects [44].…”