DFT Study of Skutterudite CoSb3 and In0.2Co4Sb12 Thermoelectric Heterostructures with 2D–WSe2. Issue 32 (27th August 2018)

• Record Type: Journal Article
• Authors: Kiarii, Ephraim Muriithi; Govender, Krishna Kuben; Mamo, Messai Adenew; Govender, Penny Poomani
• Is Part Of: ChemistrySelect. Volume 3:Issue 32(2018)
• Page Start: 9336
• Page End: 9347
• Publication Date: 2018-08-27
• Subjects: Electronic -- Heterostructures -- Optical -- Skutterudites -- Two–dimensional WSe2; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201801870
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: 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 In0.2 Co4 Sb12 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 /In0.2 Co4 Sb12 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 In0.2 Co4 Sb12 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. Abstract : In this study, visible light and infrared absorption of heterostructures were observed, as well as a lower electron affinity and ionisation energy relative to the starting thermoelectric materials. This indicated that combining WSe with CoSb3 could serve as an electron donor due to its low ionisation energy in the heterostructures. The charge transfer study revealed a built–in potential at the interface, which ensured easy separation of heat generated carriers and thus, improved the thermoelectric performance.