Characterization of large-volume Frisch grid detector fabricated from as-grown CdZnTeSe

Abstract

CdZnTe (CZT) has been under continuous development as a room-temperature radiation detector for the past 2-3 decades. Due to its intrinsic defects, such as a high concentration subgrain boundary network, it has been very challenging to consistently produce high-quality CZT detectors with high yield, particularly for detector volumes exceeding a few cubic centimeters. In this paper, we report characterization of a relatively large-volume Frisch-grid detector (dimensions: 11 × 10.8 × 19.4 mm3) fabricated from a new material Cd0.9Zn0.1Te0.985Se0.015. The detector was fabricated from an as-grown ingot with a 2-in. diameter grown by the Traveling Heater Method. The detector sample was evaluated by infrared transmission microscopy to study the presence of Te inclusions. X-ray topography using a synchrotron light source was deployed to measure the presence of subgrain boundaries and their networks. The detector performance was measured for an optimized Frisch-grid length to extract the best energy resolution at room temperature.