Enhanced thermoelectric properties in Sb/Ge core/shell nanowires through vacancy modulation

Abstract

In the present work, we have modified the physical and electronic structure of Sb/Ge core/shell nanowires via vacancy creation and doping with foreign atoms with the aim to improve their thermoelectric energy conversion efficiency. Sb/Ge-NWs having a diameter of 1.5 Å show metallicity with 2Go quantum conductance. The stability of the nanowires is assessed through the calculation of their formation energy. The formation of one vacancy at either the Sb- and Ge-site modifies substantially the electronic properties. From the comparison of the thermoelectric properties of the nanowires with and without the vacancy, we have found that the figure of merit for the Sb/Ge NW with one Sb vacancy increases of 0.18 compared to the pristine NW. The NW doping with different transition metals: Fe, Co, Ni and Cu have been found to also enhance the conversion efficiency. Thus, our calculations show that the thermoelectric performance of metal–semiconductor core–shell NWs can be in principle improved as much as 80% by vacancy formation and doping.

Optimizing the quantum capacitance of AsXBr/AsYBr ((X ≠ Y) = S, Se and Te) Janus heterostructures for high-performance supercapacitors

“…Thermoelectric materials have garnered significant attention in the scientific community due to their remarkable ability to harness waste heat and convert it into clean electricity, [77][78][79] offering a potential solution to address energy and environmental challenges by making use of an otherwise underutilized energy source and contributing to sustainable and eco-friendly energy solutions. To assess a material's thermoelectric capabilities, it is crucial to determine its key thermoelectric characteristics, namely the Seebeck coefficient (S), electronic conductivity (s), and thermal conductivity (k).…”