Abstract
Large volume single crystals of CdTe and Cd0.9Zn0.1Te (CZT) have been grown by a controlled vertical Bridgman
technique using in-house zone refined precursors and characterized through structural, electrical, optical, and
spectroscopic methods. The grown crystals (diameter greater than or equal to 2.5 cm and length >10 cm) have shown promising characteristics
for high-resolution room temperature solid-state radiation detectors due to their high resistivity (~1010 Ω-cm for CdTe,
and >1011 Ω-cm for CZT) and good charge transport properties [μτe ~ (2-5)x10-3 cm2/V]. The fabricated detectors in
planar single element and Frisch collar configurations have shown very low leakage currents and high count rates for
various sources, including Am-241, and Cs-137. The grown crystals have been further characterized by X-ray diffraction
(XRD), infrared spectroscopy (IR), and transmission two-modulator generalized ellipsometry (2-MGE). Details of the
CdTe and CZT characterization results, detector fabrication steps, and testing with radiation sources are presented. The
CdTe and CZT crystals have shown high prospects for low power rating solid-state nuclear spectrometers and medical
imaging devices.
