Proceedings Article | 8 September 2011
Proc. SPIE. 8191, International Symposium on Photoelectronic Detection and Imaging 2011: Sensor and Micromachined Optical Device Technologies
KEYWORDS: Infrared imaging, Sensors, Crystals, X-rays, X-ray diffraction, Sensor performance, X-ray imaging, X-ray detectors, Infrared microscopy, Tellurium
Cadmium Zinc Telluride (CdZnTe or CZT) is a very attractive material for room-temperature semiconductor detectors
because of its wide band-gap and high atomic number. Despite these advantages, CZT still presents some material
limitations and poor hole mobility. In the past decade most of the efforts developing CZT detectors focused on
designing different electrode configurations, mainly to minimize the deleterious effect due to the poor hole mobility. A
few different electrode geometries were designed and fabricated, such as pixelated anodes and Frisch-grid detectors
developed at Brookhaven National Lab (BNL). However, crystal defects in CZT materials still limit the yield of
detector-grade crystals, and, in general, dominate the detector's performance. In the past few years, our group's
research extended to characterizing the CZT materials at the micro-scale, and to correlating crystal defects with the
detector's performance. We built a set of unique tools for this purpose, including infrared (IR) transmission microscopy,
X-ray micro-scale mapping using synchrotron light source, X-ray transmission- and reflection- topography, current deep
level transient spectroscopy (I-DLTS), and photoluminescence measurements. Our most recent work on CZT detectors
was directed towards detailing various crystal defects, studying the internal electrical field, and delineating the effects of
thermal annealing on improving the material properties. In this paper, we report our most recent results.
