Enhanced thermoelectric performance of n-type bismuth selenide doped with nickel

Bismuth selenide (Bi2Se3) and transition metal (nickel) doped (5 and 7.5 mol %) Bi2Se3 have been prepared by solvothermal approach for investigation of thermoelectric properties of the materials. The morphological characterization reveals plate and flake like structures for undoped and doped samples respectively. There is a decrease in lattice constant, computed from Rietveld refinement data and crystallite size, found using Debye-Scherrer equation for doped samples. Doping by nickel increases the electrical conductivity and reduces both thermo power and thermal conductivity of the materials than pure Bi2Se3. Reduction in thermal conductivity of the doped samples by 42%, results in an increase in figure of merit (ZT) of nickel doped (5%) materials by one order of magnitude (0.02-0.22) compared to pure Bi2Se3. (C) 2017 Elsevier B.V. All rights reserved.