The effects of crystal geometry and aspect ratio on a CdZnTe Frisch collar device were investigated. A 19.08x19.34x4.95mm³ device fabricated from CdZnTe grown by Redlen Technologies was used as the starting material. The crystal was re-fabricated many times to achieve several aspect ratios while the device length was held constant at 4.75±0.15mm. The following aspect ratios were successfully fabricated from the initial device: 0.26, 0.52, 0.71, 0.96, 1.19, 1.36, 1.59 and 1.92. The energy spectra of ²⁴¹Am and ¹³⁷Cs were recorded for all devices in both planar and Frisch collar configurations. The current-voltage (I-V) characteristic curve was also determined for planar configurations. It was observed that the Frisch collar effect begins to occur for devices with an aspect ratio of approximately 1.0. Device performance continued to improve as the aspect ratio was further increased and was noted to significantly improve the energy resolution of the device when the aspect ratio was greater than 1.5. The CdZnTe devices were also theoretically modeled to support the experimental conclusion.

Date Published: 24 September 2007
PDF: 17 pages
Proc. SPIE 6706, Hard X-Ray and Gamma-Ray Detector Physics IX, 67061J (24 September 2007); doi: 10.1117/12.740472

Published in SPIE Proceedings Vol. 6706:
Hard X-Ray and Gamma-Ray Detector Physics IX
Ralph B. James; Arnold Burger; Larry A. Franks, Editor(s)