A new explanation of the Cl donor deionization and its kinetics observed in CdTe: Cl under hydrostatic pressure

Measurements of the Hall coefficient in CdTe:Cl at pressures up to 14 kbar and at temperatures ranging from 77 to 297 K reveal the deionization of the Cl donor level. In the vicinity of T = 150 K, at constant pressure, the relaxation time of the deionization process is of the order of hours. The experimental data are explained using the model of a donor centre with two non-equivalent lattice positions separated by a potential barrier. The height of the potential barrier is determined to be about 0.55 eV. The observed deionization – in the light of this model – is not a purely electronic process, but consists of two different processes. These are the change of the Cl donor charge state and the transfer of the donor between its both lattice positions.