Experimental Analysis of Noise in CdTe Radiation Detectors

Noise characteristics of CdTe gamma and X-ray detectors have been carried out. Samples were prepared at Physical Institute of Charles University in Prague by traveling heater method (THM). Measurements of high-ohmic detectors with two golden contacts and low-ohmic detectors with four contacts were carried out. Two voltage contacts were used to distinguish between metal-semiconductor junction area with depleted region and homogeneous part of the sample. The resistance of high-ohmic samples is in the range from hundreds of M' up to several G'. The noise characteristics of the samples were measured in dark and with the illumination in the range of radiation from ultraviolet to infrared.