Abstract
Thallium bromide(TlBr) is a compound semiconductor with band-gap energy of 2.68eV. High photon stopping power is one of the most attractive physical properties of TlBr, originating from its high density (7.56g/cm^3) and high atomic numbers of the constituent elements (Tl and Br). Thus, TlBr is a promising semiconductor material for fabrication of gamma-ray spectrometers operating at room temperature. The T1Br crystals grown by the traveling molten zone method have exhibited the charge transport properties comparable to commercially available gamma-ray detector grade CdTe crystals. A TlBr detector with small pixels has exhibited an energy resolution of approximately 1% for 662keV gamma-rays at room temperature. Significant suppression of polarization phenomena in TlBr detectors has been achieved by adopting Tl metal as the electrode material for TlBr detectors. By changing the polarity of the applied bias voltages every 24 hours, the TlBr detectors with Tl electrode have exhibited stable spectroscopic performance for 600 hours.
