Influence of crystalline surface quality on TlBr radiation detector performance

In this study, TlBr detectors were fabricated from crystals purified by the multipass zone refining and grown by the Bridgman method. Detectors were prepared using TlBr 0.3-mm-thick wafers, with surface submitted to different mechanical and chemical treatments. Optical microscopy and scanning electron microscopy evaluated the TlBr wafers surface quality. To analyze the surface quality influence in the detector response, systematic measurements of the pulse height spectra and energy resolution were carried out for each prepared radiation detector. The radiation response for these detectors was performed under ²⁴¹Am gamma radiation excitation at room temperature. The influence of the surface quality of the TlBr wafer on its performance as a radiation detector was observed.