Optical and thermal spectroscopy of vanadium-doped CdTe and related photorefractive effect

The energy level diagram of substitutional vanadium in CdTe (and also Cd _0.96Zn _0.04Te) has been investigated by using a variety of optical and thermal spectroscopy techniques: optical absorption, photoconductivity, photoluminescence, deep level optical spectroscopy, DLTS and thermally stimulated current (PICTS). This study has led to set the V ²⁺/V ³⁺ level at 0.95 eV below the conduction band with an optical photoionization threshold at 1.03 eV. Two-wave mixing experiments were used to evaluate the photorefractive properties. Gain coefficients in excess of 10 cm ^-1 have been measured at λ = 1.32 μm with applying a 40 Hz AC electric field.