Applied Physics Department, Sardar Vallabhbhai National Institute of Technology, Surat 95007, India.
Phys Chem Chem Phys. 2018 Nov 21;20(45):28575-28582. doi: 10.1039/c8cp04723e.
Motivated by the recent success in the experimental synthesis of two-dimensional group-III monochalcogenides, we investigate the structural, electronic and thermoelectric properties of GaS, GaSe and GaTe monolayers based on the first-principles approach by using density functional theory and the semi-classical Boltzmann transport equation. The electronic band structures demonstrate that the GaS, GaSe, and GaTe monolayers are wide bandgap semiconductors having an indirect bandgap of 3.73 eV, 3.27 eV, and 2.46 eV respectively. We have evaluated the thermoelectric properties comprising the Seebeck coefficient, electrical conductivity per relaxation time, electronic thermal conductivity per relaxation time, electronic specific heat, thermoelectric figure of merit and power factor at various temperatures from 50 K to 800 K. It is found that GaS, GaSe and GaTe monolayers could be suitable candidates for low temperature efficient thermoelectric materials because of the high value of the thermoelectric figure of merit below room temperature.
受二维 III 族单硫属化物实验合成近期成功的启发，我们基于第一性原理方法，通过密度泛函理论和半经典玻尔兹曼输运方程，研究了 GaS、GaSe 和 GaTe 单层的结构、电子和热电性质。电子能带结构表明，GaS、GaSe 和 GaTe 单层是宽带隙半导体，具有 3.73 eV、3.27 eV 和 2.46 eV 的间接带隙。我们评估了热电性质，包括不同温度（50 K 至 800 K）下的塞贝克系数、每弛豫时间的电导率、每弛豫时间的电子热导率、电子比热、热电优值和功率因子。结果表明，由于室温以下热电优值较高，GaS、GaSe 和 GaTe 单层可能是低温高效热电材料的候选材料。
