Two-dimensional modeling of Cd(Zn)Te strip detectors

Although there has been significant recent progress in the development of CdTe and CdZnTe radiation detectors, these materials are still plagued by charge trapping and recombination problems. Recent work has shown that fabrication of arrays with small anodes can overcome these problems to some extent. The purpose of this simulation study was to investigate this small anode effect in relatively large strip detectors of various geometries. Unlike previous simulations, the current study includes the effects of both trapping and detrapping, significant inter-pixel spacing, and non-linear electric field profiles. In addition, the methods have the potential to account efficiently for spatial variations in trapping behavior and for multiple trapping levels. The results of the simulation predict that 8 mm thick strip detectors with 1 mm anode thickness and 0.3 mm anode spacing will provide adequate performance for our medical imaging application.