Growth and transport property measurements of rhenium doped tungsten diselenide single crystal

Abstract

Single crystals of rhenium doped tungsten diselenide i.e. Re x W 1− x Se 2 ( x = 0, 0.0005, 0.001, 0.05, 0.1) are grown by vapour phase technique. The stoichiometry of grown single crystals is confirmed by energy dispersive analysis of X-rays. X-ray powder diffractograms obtained of these compounds were used for lattice parameter determination based on hexagonal system similar to that of host WSe 2.The crystallite size for each sample for different reflection is calculated using Scherrer's formula. Surface morphology as observed under optical microscope reflects that screw dislocation mechanism is responsible for growth of crystals. Electrical properties viz. Hall effect at room temperature, resistivity measurements at low temperature, and high pressure resistivity measurements indicates the semiconducting behaviour of Re x W 1− x Se 2 ( x = 0, 0.0005, 0.001, 0.05, 0.1) single crystals. Thermoelectric power measurements shows p-type nature of host WSe 2 whereas n-type nature of rhenium doped WSe 2 which matches with the results of Hall effect.