High-resolution Schottky CdTe diode detector

We describe recent progress on,the use of Schottky CdTe diode detectors for spectrometry. The low leakage current of the CdTe diode allows us to apply a much higher bias voltage than was possible with previous CdTe detectors. For a relatively thin detector of 0.5-1 mm thickness, the high bias voltage results in a high electric field in the device. Both the improved charge-collection efficiency and the low-leakage current lead to an energy resolution of better than 600 eV full-width at half-maximum at 60 keV for a 2 x 2 mm(2) device without any charge-loss correction electronics. Large-area detectors with dimensions of 21 x 21 mm2 are now available with an energy resolution of similar to2.8 keV. Long-term stability can be easily attained for relatively thin (< 1 mm). detectors if they are cooled or operated under a high bias voltage.