In this work we measured the crystal defect levels and tested the performance of CdZnTe detectors by diverse
methodologies, viz., Current Deep Level Transient Spectroscopy (I-DLTS), Transient Current Technique (TCT),
Current and Capacitance versus Voltage measurements (I-V and C-V), and gamma-ray spectroscopy. Two important
characteristics of I-DLTS technique for advancing this research are (1) it is applicable for high-resistivity materials (>106
Ω-cm), and, (2) the minimum temperature for measurements can be as low as 10 K. Such low-temperature capability is
excellent for obtaining measurements at shallow levels.
We acquired CdZnTe crystals grown by different techniques from two different vendors and characterized them for point
defects and their response to photons. I-DLTS studies encompassed measuring the parameters of the defects, such as the
energy levels in the band gap, the carrier capture cross-sections and their densities. The current induced by the laser-generated
carriers and the charge collected (or number of electrons collected) were obtained using TCT that also
provides the transport properties, such as the carrier life time and mobility of the detectors under study. The detector's
electrical characteristics were explored, and its performance tested using I-V, C-V and gamma-ray spectroscopy.