Correlation between the optical and the magnetic properties of defects in photorefractive CdTe:Ge

Abstract The optimisation of CdTe:Ge for photorefractive applications at useful wavelengths requires the characterisation of a number of deep defects and an understanding of their role in recharging processes. We have investigated crystals of several origins via optical absorption and photoabsorption (PA), magnetic circular dichroism (MCD) and the optical detection of magnetic resonance (ODMR). Photoabsorption provides quantitative information about optical cross-sections of ionisation while MCD indicates the occurrence of several paramagnetic species and enables the monitoring of their relative concentrations. Besides a very clear identification of the ionised donor GeCd+, ODMR shows the presence of several uncompletely identified defects.