Photocapacitance study of defects in plastically-deformed CdTe

Abstract

Deformation-induced defects have been investigated in both n- and p-type CdTe by photocapacitance measurements (PCM). Two deep levels were observed in similar concentrations near the middle of the gap. The corresponding defects are supposed to be identical with those that have been found by other authors, using deep-level transient spectroscopy. From a fit of our data to models of the absorption cross-section we obtain the photo-ionization energies and can reliably estimate the activation enthalpies of the relaxed defect states, taking into account the electron—phonon interaction. The Huang—Rhys factor for the electron—phonon coupling of both states is of the order of twenty.