Investigations of trapping centers were carried out on polycrystalline films by using thermally stimulated conductivity techniques. The measurements were performed at temperatures ranging from 80 to 300K. The thermally stimulated conductivity spectra exhibited 3 peaks which were related to 3 trapping levels with activation energies of 0.18, 0.29 and 0.32eV. The first 2 trapping levels corresponded to known acceptor centers in bulk CdTe. It was suggested that the level at 0.32eV was due to grain boundary defects that were characteristic of polycrystalline films.

R.Ramírez-Bon, F.J.Espinoza-Beltrán, O.Vigil, O.Zelaya-Angel, F.Sánchez-Sinencio, J.G.Mendoza-Alvarez, D.Stolik: Journal of Applied Physics, 1995, 78[6], 3908-11