AUTHOR=Kim Hadong , Ogorodnik Yaroslav , Kargar Alireza , Cirignano Leonard , Thrall Crystal Lynn , Koehler William , O'Neal Sean Patrick , He Zhong , Swanberg Erik , Payne Stephen A. , Squillante Michael R. , Shah Kanai TITLE=Thallium Bromide Gamma-Ray Spectrometers and Pixel Arrays JOURNAL=Frontiers in Physics VOLUME=8 YEAR=2020 URL=https://www.frontiersin.org/journals/physics/articles/10.3389/fphy.2020.00055 DOI=10.3389/fphy.2020.00055 ISSN=2296-424X ABSTRACT=

Thallium bromide (TlBr) is a compound semiconductor with a band gap of 2.68 eV making it ideal for room temperature radiation detection. The high atomic numbers, 81 and 35, and the high density of 7.56 g/cm3 give it excellent gamma-ray stopping power. TlBr is a cubic material that melts congruently at a relatively low temperature (~480°C). These properties make it relatively easy to grow good quality crystals with high yield. As a result of improvements in the purification of TlBr mobility-lifetime product of electrons, μτe, is now on the order of 10−2 cm2/V, which is similar to that of CZT. High μτe enables the fabrication of thicker detectors with good charge collection and energy resolution. The properties of TlBr make it ideal for use in room temperature gamma radiation operation [1]. Single carrier devices such as small pixel arrays [2] and Frisch collar devices [3] which were developed for CZT can also been applied to TlBr. For example, better than 1% FWHM at 662 keV has been obtained for single pixel events with small (e.g., 3 × 3 pixels, 1-mm pitch, 5-mm thick) arrays.