Attempt to Impart Conductivity to Thallium Bromide by Thermal Diffusion Doping

As part of the development of thallium bromide (TlBr) semiconductor detectors, impurity doping into TlBr by the thermal diffusion method was attempted, along with the exploration of ohmic electrodes.Dopant materials with ionic radii and valence similar to those of Tl or Br were selected.In TlBr samples of 1 mm thickness, Sr and Pb doping improved the leakage current by approximately 8 times compared with undoped samples under an applied voltage of -100 V. Various metal electrodes were formed on TlBr samples doped with Sr or Pb, and their I-V characteristics were evaluated.Rectifying properties were observed in the Pb-doped samples with Ti and In, as well as in the Sr-doped samples with Ti.These results suggest that Sr-doped TlBr and Ti may have potential for use as injection electrodes.