Annealing and characterisation of TlBr crystals for detector applications

Single crystal TlBr is a promising material as a room temperature X- and gamma-ray detector. The TlBr detector performance is generally limited by the purity and crystal quality of the initial material. These problems are related to raw material purity, the crystal growth method and further detector manufacturing processes. The purpose of this work was to study the effect of crystal quality and annealing, under an argon atmosphere and in pure water under hydrothermal conditions, on the electrical, optical and X-ray detection properties of TlBr. The samples were characterised by polarised light and by current-voltage (I-V) and photocurrent measurements. They were also studied under Cu-radiation from an X-ray powder diffractometer.