Evaluation of CdZnTe detectors for soft X-Ray applications

High resistivity CdZnTe is a very promising material for X-ray detection at room temperature or slightly below. Cooling a Cd/sub 0.8/Zn/sub 0.2/Te crystal down to -30/spl deg/C reduces the leakage current to the picoamp level, which enables the use of low-noise pulsed optical feedback instead of noisier resistive feedback preamplifiers. Also, longer shaping time constants at the linear amplifier can be used for the optimum resolution. We have obtained resolutions of 240 eV (FWHM) for the 5.9-keV /sup 55/Fe line at -40/spl deg/C and of 282 eV at -30/spl deg/C. The Fano factor for the material at -40/spl deg/C was calculated to be 0.14. These results compare well with the results obtained with peltier-cooled HgI/sub 2/ detectors.<
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