Special technique for growing TI4S3, anisotropy of electrical conduction and photophysical properties

Single crystals of Tl4S3 were prepared by using a special local technique and the obtained crystals were analyzed by X-ray diffraction. The electrical properties (electrical conductivity and Hall effect) and steady-state photoconductivity for the resultant crystals were elucidated in this work. The electrical measurements extend from 170 to 430 K. sigma(perpendicular to) = 4.263 x 10(-6) (Omega cm)(-1) when current flow direction makes a right angle to the cleavage plane of the crystals, but sigma\\ = 1.034 x 10(-6) (Omega cm)(-1) when the current flow is parallel to the cleavage plane. The width of the band gap is calculated using the electrical conductivity and Hall Effect measurements, and the values are discussed. The anisotropy of the electrical conductivity (sigma(perpendicular to)/sigma\\) in the Tl4S3 single crystals was also studied in this work. Finally, the photosensitivity was calculated for different levels of illumination. The results of the photoconductivity study showed that the recombination process in Tl4S3 single crystals is monomolecular.