α Particle response of undoped CdMnTe

The properties required for γ-ray detection of single-crystal Cadmium Manganese Telluride (Cd1−xMnxTe) are investigated and samples are evaluated as room temperature radiation detectors. Undoped Cd1−xMnxTe crystals are characterised using sub band gap IR microscopy mapping of extended defects, room temperature photoluminescence band-gap measurements, IV measurements and α particle spectroscopy. The band gap energy calculated from room temperature near-band-edge luminescence was found to be 1.70±0.01 eV, corresponding to a manganese fraction in the sample of x=0.13. The hole mobility-lifetime product was measured at 150 K and was found to be of the order of 1×10−5 cm2/V.