Noise Sources in the CdTe radiation detectors

摘要

Noise and transport characteristics of CdTe gamma - and X-ray detectors have been carried out to determine the 1/f noise sources and theirs correlation with charge carriers mobility. The noise spectral density was measured by standard set-up. The noise of low ohmic samples has 1/f noise spectral density which increases with the square of voltage. The high ohmic samples revile 1/f type noise in low frequency range and G-R noise in frequency above 100 Hz. In low frequency range noise spectral is proportional to fourth power of current and then we suppose that main source of noise is in Schottky barrier in vicinity of contacts. We suppose that thickness of the region with dominant contribution to noise decreases with increasing current and total reciprocal number of curriers is proportional to second power of current. Then current noise spectral density is proportional to fourth power of current.