Thermoelectric performance of monolayer Bi2Te2Se of ultra low lattice thermal conductivity

Abstract

The electronic structure and thermoelectric properties of monolayer Bi2Te2Se were studied by density functional theory and semi-classical Boltzmann transport equation. The band gap with TB-mBJ can be improved for monolayer Bi2Te2Se. Monolayer Bi2Te2Se have ultra-low thermal conductivity comparing with other well-known two-dimensional materials. The monolayer Bi2Te2Se can improve electrical conductivities. ZT increases with increasing temperature for monolayer Bi2Te2Se. Comparing to GGA, TB-mBJ has larger ZT value in p-type doping. Monolayer Bi2Te2Se have larger ZT comparing with other well-known two-dimensional materials. Our calculated results show that our calculation greatly underestimates ZT value, therefore, monolayer Bi2Te2Se should have a higher ZT value.