Noise and transport characteristics of CdTe gamma - and X-ray detectors have been carried out to
determine the 1/f noise sources and their correlation with charge carriers mobility. The noise spectral
density was measured by standard set-up. The no
ise of low ohmic samples has 1/f noise spectral
density which increases with the square of voltage. The high ohmic samples show 1/f type noise in low
frequency range. This flicker noise leads to degradation in the homogeneity of the contact. The excess
of noise changes as 1/fa , 1 a 2 at 10Hz, and it is due to the multitrapping of the CdTe. Thiscontributes to the loss in charge collection efficiency.