STOICHIOMETRIC DEPENDENCE OF ELECTRICAL CHARACTERISTICS IN WSSE SINGLE-CRYSTALS GROWN BY DIRECT AND CHEMICAL-VAPOR TRANSPORT TECHNIQUES

Single crystals of tungsten sulphoselenide (WSSe) have been grown by b oth direct and chemical vapour transport techniques. The crystals have been subjected to Hall effect and resistivity measurements for their electrical characterization. The observed differences in the electrica l resistivity, type of conduction, and activation energy have been att ributed to the stoichiometric differences between the crystals grown b y the two techniques. The crystals grown by chemical vapour transport technique with iodine as the transport agent have been found to be mor e stoichiometric.