The influence of electron track lengths on the γ-ray response of compound semiconductor detectors

The charge trapping effect in compound semiconductor gamma-ray detectors in the presence of a uniform electric held is commonly described by Hecht's relation. However, Hecht's relation ignores the geometrical spread of charge carriers caused by the finite range of primary and secondary electrons (6-rays) in the detector. In this paper, a method based on the Shockley-Ramo theorem is developed to calculate 7-ray induced charge pulses by taking into account the charge-trapping effect associated with the geometrical spread of charge carriers. The method is then used to calculate the response of a planar CdTe detector to energetic gamma-rays by which the influence of electron track lengths on the y-ray response of the detectors is clearly shown. (C) 2015 Elsevier B.V. All rights reserved.