Spectrometer performance of n-type cadmium telluride x- and γ-ray detectors

Highly perfect n-type CdTe single crystals grown by the sealed-ingot-zone refining method have been used to fabricate semiconductor surface-barrier detectors for X- and low-energ, γ-ray analysis. An energy resolution of 2.0 keV /fwhm/ and 1.5 keV /fwhm/ was achieved for 59.5 keV γ-rays from ²⁴¹Am and 5.9 keV characteristic K X-ray line from ⁵⁵Fe source, respectively. Spectra were measured at room temperature with low detector bias. The observed full energy peak of 59.5 keV γ-rays has been compared with the teoretical peak calculated for a surface-barrier junction with fixed space charge, the trapping effects being taken into account.