Persistent electron redistribution among deep levels in CdTe

Abstract

Photo electron paramagnetic resonance measurements in CdTe show that sub-band-gap illumination causes a transfer of electrons from deep Ge donors to deep Ni acceptor states at a higher energy. This metastable state persists in the dark and can be quenched by illumination with photon energies in the midgap range. The metastability is explained in terms of the strong localization of both the Ni and the Ge states.