Metallic and semiconducting Sb 2 Te 3 alloys have been synthesized by controlling the cooling rate in the solid state reaction method. Temperature dependent resistivity is measured down to 10 K for the identification of metallic and semiconducting phases. Structural studies are performed by both X-ray diffraction (XRD) and Raman spectroscopic analyses. XRD study confirms single phase nature of polycrystalline alloys in the detectable limit. Raman spectroscopy is used to understand the vibration properties of Sb 2 Te 3 crystals. Widening of full width at half maxima of the highest intense peak in the XRD analysis indicates higher amount of defects in the semiconducting phase than that in the metallic one. Raman study indicates presence of impurity phases in the semiconducting Sb 2 Te 3 . The resistivity of semiconducting Sb 2 Te 3 sample is higher than that of metallic one, which corroborates with the XRD and Raman analyses. © 2015 AIP Publishing LLC.