Thermoelectric properties of two-dimensional GaTe bilayer

Investigation of thermoelectric (TE) properties on two-dimensional (2D) materials attracts intensive research efforts due to its potential environment-friendly applications. We explore the TE properties of 2D bilayer GaTe. The GaTe bilayer has an indirect bandgap of 1.35 eV. The maximum Seebeck coefficient is 1550 mu V/K regardless of the direction and doping type. The relaxation time has anisotropic behavior. In the n-type system, the armchair direction relaxation time is longer than the zig-zag direction. The p-type relaxation time has no directional dependency and shorter than that of n-type. Also, the n-type relaxation time is longer than that of the p-type. This anisotropic relaxation time in n-type system generates larger electrical conductivity and electronic thermal conductivity in the n-type armchair direction. The lattice thermal conductivity has no directional dependency and is larger than the electronic thermal conductivity. Overall, we obtain the maximum figure of merit (ZT) of similar to 0.82 in the n-type at 700 K.