Investigation of thermoelectric properties of some thallium based materials

İn this thesis,thallium based ternary chalcogenide materials are investigated for their thermoelectric performance. Electronic and thermoelectric properties of TlSbS2 , TlSbSe2 , TlSbTe2, TlBiS2, TlBiSe2, TlBiTe2 materials are calculated with and without spin-orbit coupling effect using density functional theory and generalized gradient approximation. By calculating total and partial density of states, the contributions to the valance and conduction bands from orbitals are presented. The seebeck coefficients, electrical conductivity, electronic thermal conductivity, power factors and the estimated ZT values are calculated are discussed with available experiments are calculations.