Characterization of Spatial Heterogenieties in Detector Grade CdZnTe

Published

December 4, 2007

Author(s)

Martine Duff, Douglas Hunter, Arnold Burger, Michael Groza, V Buliga, J Bradley, G Graham, Z Dai, N Teslich, David R. Black, H E. Burdette, A Lanzirotti

Abstract

Synthetic Cd1-xZnxTe or CZT crystals are highly suitable for the room temperature-based spectroscopy of gamma radiation. Structural/morphological heterogeneities within CZT, such as secondary phases that are thought to consist of Te metal, can have negative impacts on detector performance. In this study, we used electron and X-ray-based imaging techniques to examine heterogeneous properties of a detector grade CZT crystal. Our study identifies two dominant types of secondary phase morphologies. The first of these are numerous empty 20 ?m pyramidal bodies (tetrahedra) or negative crystals that contain trace quantities of particulate residue that exist as 65 nm sized particles of Si, Cd, Zn, and Te. The other types are 20 ?m hexagonal-shaped bodies, which are actually composites consisting of metallic Te layers that contain teardrop-shaped inclusions of amorphous and polycrystalline CdZnTe and finally a void core. These Te-rich composites appear as raised features on the polished faces of the Cd-rich and the Te-rich CZT surfaces. Although traditionally these two morphologies have been treated as a similar crystal defect, the mechanisms for formation, as well as their individual influence on the detector performance could be different and are yet to be elucidated.

Citation

Science

Pub Type

Journals

Keywords

CdZnTe, characterization, detector, heterogeneities

Citation

Duff, M. , Hunter, D. , Burger, A. , Groza, M. , Buliga, V. , Bradley, J. , Graham, G. , Dai, Z. , Teslich, N. , Black, D. , Burdette, H. and Lanzirotti, A. (2007), Characterization of Spatial Heterogenieties in Detector Grade CdZnTe, Science (Accessed April 19, 2024)