Use of various device geometries to improve the performance of CdTe detectors

Abstract

Cadmium telluride detectors were fabricated from semi-insulating material (p > 107 Ω. cm) with different geometries so as to take advantages of the superior mobility-trapping time products of electrons (μeτ e+ = 6-10 × 10-4 cm2/V) as compared to those of holes (μhτh+ ~ 5 × 10 -6 cm2/V) and suit different ranges of photon energies. In the case of X-ray detectors, plane parallel devices were fabricated with active areas up to 3 cm2. For the case of high energy more penetrating radiation, cube shaped detectors, having nonuniform electric fields, were fabricated. Arrays were also made from such cubes to evaluate their potential use in imaging applications at room temperature. Where a small frontal area but high efficiency is required, such as in ablation studies for reentry vehicles, bar-shaped detectors, 3 mm x 7 mm and up to 2 cm in length are appropriate and were also fabricated