Relationship between deep levels in vanadium-doped CdTe and photorefractive effect

We present electro-optical characterization (by deep level transient spectroscopy, deep level optical spectroscopy and photo-induced current transient spectroscopy) on vanadium doped CdTe and CdZnTe crystals prepared by the vertical Bridgman method for photorefractive applications. Two main electron traps at 0.95 and 0.78 eV were detected and characterized. These levels are strongly involved in the photorefractive effect of CdTe doped with V, and led to distinguish two classes of crystals.