Investigation of structural, electrical and optical properties of SbXW1-XSe2 single crystals

This article presents systematic studies of SbXW1-XSe2 (X = 0, 0.1) single crystals grown by direct vapour transport technique. The purity and stoichiometry were tested by energy dispersive analysis of X-ray (EDAX). To explore lattice structure of grown compounds, powder X-ray diffraction was performed. A surface morphology of Sb0.1W0.9Se2 crystals was checked by optical microscope and scanning electron microscope. The transmission electron microscopy was also used to verify the crystallinity of grown samples. The variations of electrical resistivity parallel and perpendicular to c-axis were measured in the temperature range from 303 to 673 K. The results showed semiconducting behaviour and anisotropic charge conduction of grown single crystals. The n-type semiconducting nature was confirmed by Hall-effect measurements. The optical band gap was determined by UV-Visible-NIR spectroscopy. The Raman spectrum was also taken from grown SbXW1-XSe2 (X = 0, 0.1) single crystals using excitation of 785 nm. The obtained results suggest the substitutional doping of Sb+5 on W+4 lattice site.