Comparative evaluation of the temperature dependence of different noise sources in CdTe detectors

The number of applications of CdTe detectors for imaging purposes is currently growing at a fast rate. Nevertheless, noise is still a limiting factor in several circumstances, particularly when a high dynamic range is needed. Thus, knowledge of the comparative importance of various noise sources (mainly referring to the dark current in the detector, the electronic noise in the preamplifier and the statistical noise) is valuable for the development of efficient noise reduction techniques. The dependence on temperature of these noise sources has been evaluated over the range from - 30 degrees C up to 40 degrees C. Although some components of the noise show a marked temperature dependence, the overall detector spectroscopic performances are constant up to 10 degrees C, while above this level an appreciable degradation occurs.