Density of states effective mass of SnBi4Se7 deduced from the temperature dependence of electrical conductivity in the activation regime

Abstract

Current–voltage (I–V) measurements on polycrystalline samples of Bi2Se3 and stoichiometric ternary compound in the quasi-binary system of SnSe–Bi2Se3 at different temperatures in the vicinity of room temperature have been performed. Also, temperature dependence of electrical conductivity has been measured. From the analysis of the temperature dependence of electron concentration in the activation regime above room temperature, the density of states effective mass, m*, has been determined. Some intrinsic and contact properties such as barrier heights, ideality factors, and carriers concentrations have been investigated using I–V characteristics. It has been found that all samples exhibit ohmic and space charge limited conduction at low and high fields, respectively.