DFT Study on the Carrier Concentration and Temperature-Dependent Thermoelectric Properties of Antimony Selenide

Abstract

We present the thermoelectric properties of Antimony Selenide (Sb 2 Se 3 ) obtained using first principles calculations. We investigated the electronic band structure using the FP-LAPW method within the sphere of the density functional theory. Thermoelectric properties were calculated using BoltzTrap code using the constant relaxation time ( τ ) approximation at three different temperatures 300 K, 600 K, and 800 K. Seebeck coefficient ( S ) was found to decrease with increasing temperature, electrical conductivity ( σ / τ ) was almost constant in the entire temperature range, and electronic thermal conductivity ( κ / τ ) increased with increasing temperature. With increase in temperature S decreased from 1870 μ V/K (at 300 K) to 719 μ V/K (at 800 K), electronic thermal conductivity increased from 1.56 × 10 15 W/m K s (at 300 K) to 3.92 × 10 15 W/m K s (at 800 K), and electrical conductivity decreased from 22 × 10 19 /Ω m s (at 300 K) to 20 × 10 19 /Ω m s (at 800 K). The thermoelectric properties were also calculated for different hole concentrations and the optimum concentration for a good thermoelectric performance over a large range of temperatures (from 300 K to 1000 K) was found for hole concentration around 10 19 cm −3 .