CdTe and CdZnTe crystals for room temperature gamma-ray detectors

CdTe(Cl) detectors from CdTe single crystals, grown by the Bridgman method from Te-rich melt, were fabricated. The quality of the detectors was tested with ⁵⁷Co and ²⁴¹Am sources. In the ⁵⁷Co spectrum low noise is demonstrated by the presence of a 14 keV peak and good resolution ≈7 keV (FWHM) evident from the separation of 122 and 136 keV peaks. A review is given of the state-of-the-art properties of (CdZn)Te single crystals prepared for substrates in the Institute of Physics of Charles University. The quality of samples is tested by measurements of the diffusion length of minority carriers, from which the mobility-lifetime product is evaluated.