Improved Process for the Detector Grade TlBr Single Crystals

The single crystal TlBr is a promising candidate as a room temperature gamma-ray detector due to its high stopping power, density (7.56 g/cm³) and bandgap (2.68 eV). However, material purity and crystal quality still limit the use of TlBr as detector. In this work, material was purified by hydrothermal recrystallization in pure water and traveling molten zone (TMZ) method that was used and for the single crystal growth. A sample of 4 mm thickness was characterized by the X-ray rocking curve method and optically under polarized light. The electrical properties of crystal TlBr were studied by leakage current measurements at -20 divide -42degC. Spectroscopic properties of TlBr were characterized by the pulse-height spectra of ⁵⁵Fe and ¹⁰⁹Cd at the same temperature region. The observed results are reported and discussed.