Characterisation of Redlen high-flux CdZnTe

CdZnTe is a promising material for the current generation of free electron laser light sources and future laser-driven gamma-ray sources which require detectors capable of high flux imaging at X-ray and gamma-ray energies (> 10 keV). However, at high fluxes CdZnTe has been shown to polarise due to hole trapping, leading to poor performance. Novel Redlen CdZnTe material with improved hole transport properties has been designed for high flux applications. Small pixel CdZnTe detectors were fabricated by Redlen Technologies and flip-chip bonded to PIXIE ASICs. An XIA Digital Gamma Finder PIXIE-16 system was used to digitise each of the nine analogue signals with a timing resolution of 10 ns. Pulse shape analysis was used to extract the rise times and amplitude of signals. These were measured as a function of applied bias voltage and used to calculate the mobility (mu) and mobility-lifetime (mu tau) of electrons and holes in the material for three identical detectors. The measured values of the transport properties of electrons in the high-flux-capable material was lower than previously reported for Redlen CdZnTe material (mu(e)tau(e) similar to 1 x 10(-3) cm(2)V(-1) and mu(e) similar to 1000 cm(2)V(-1)s(-1)) while the hole transport properties were found to have improved (mu(h)tau(h) similar to 3 x 10(-4) cm(2)V(-1) and mu(h) similar to 100 cm(2)V(-1)s(-1)).