Regensburg 2019 – wissenschaftliches Programm
HL 45.27: Poster
Donnerstag, 4. April 2019, 18:30–21:00, Poster E
Influence of defect and impurities in tin telluride nanowires: a theoretical study — Tainá Matendal de Souza, Maicon Luan Stefan, Fellipe de Souza Reis, and •Ernesto Osvaldo Wrasse — Universidade Tecnológica Federal do Paraná, Toledo, Brazil
A crescent demand of energy, and the necessity of renawable sources of energy, has increased the interess of materials that present a high thermoelectric efficiency, defined by the figure of merit ZT. Tin telluride (SnTe) is one of the most promissing materials for apllications in thermoelectricity. Recent works suggest that SnTe nanowires have a greather thermoelectric efficiency when compared to the bulk, and n-type doping can improve significantly the value of ZT. In this contribution, quantum mechanical calculations in the framework of the Density Functional Theory (DFT)as implemented in the VASP code, were employed to describe SnTe nanowires. The influence of intrinsic defects (vacancies and antisites) and group III impurities (Al, Ga, In, and Tl) in the structural and electronic properties were analised. Similar as obtained in SnTe bulk phase, Sn vacancie has the lowest formation energy among all the defects in SnTe nanowires. Due defect levels, the system became a p-type semiconductor. For the impurities, Ga and Tl substitutional to Sn atoms have the lowest formation energy, and give rise to a n-type semiconductor character in the SnTe nanowires. As a resume, by combining quantum confinement and doping, our results show that SnTe nanowires are good candidates for applications in efficient thermoelectric devices.