DFT Study of Skutterudite CoSb₃ and In_0.2Co₄Sb₁₂ Thermoelectric Heterostructures with 2D–WSe₂

Recently, two–dimensional WSe₂ transition–metal dichalcogenides have been used for novel electronic devices. However, its influence on the electronic and optical properties of thermoelectric Skutterudite CoSb₃ and In_0.2Co₄Sb₁₂ is unknown. Despite the increased potential of energy conversion obtained by doping CoSb₃ with indium, further theoretical study is necessary to understand the origin of this enhancement. Heterostructures of hybrid WSe₂/CoSb₃ and WSe₂/In_0.2Co₄Sb₁₂ are investigated in this study using a density functional theory calculation. The electronic structure, energy, geometry optimisation and optical properties are analysed for the individual components in the heterostructure. The obtained results show that pure CoSb₃ has a bandgap of 0.456 eV, and In_0.2Co₄Sb₁₂ has a zero bandgap, while the calculated bandgap for WSe₂ is found to be 1.482 eV. The heterostructures show an exceptional absorption in the infrared region where the heat energy mainly dominates. The charge transfer study indicates a built–in potential at the interface, which ensures easy separation of charge generated carriers and thus, improved the thermoelectric performance.