Characterization of the polarization process in thallium-bromide detectors

Having a high atomic number (Tl: 81, Br: 35), high density (7.56 g/cm³), and wide band gap (2.68 eV), thallium-bromide is a favorable candidate material for room-temperature semiconductor detector applications. Indefinite stability of TlBr detectors may be achieved by operating at -20° C. However, at room temperature, the duration of stability for TlBr detectors is currently limited due to the polarization process. While the restriction in operating temperature does not inhibit its practical use, the polarization phenomenon at room temperature is an interesting property of TlBr detectors worth investigating. In this work we study the change in charge transport and spectroscopic performance during the polarization process for multiple TlBr detectors.