Effects of surface passivation by lithium on the mechanical and electronic properties of silicon nanowires
Por:
Salazar, F., Perez, L. A., Cruz-Irisson, M.
Publicada:
1 dic 2016
Resumen:
In this work, we present a density functional theory study of the mechanical and electronic properties of silicon nanowires (SiNWs) grown along the [111] crystallographic direction with a diamond structure and surface passivated with hydrogen (H) and lithium (Li) atoms. The study is performed within the local density approximation by applying the supercell method. The results indicate that the energy gap is a function of the Li concentration and the nanowire diameter. Furthermore, the Young's modulus (Y) increases as the nanowire diameter increases, consistent with experimental reports. The increase in the Li concentration at the surface leads to a larger Y value compared to the Y value of the completely H-passivated SiNWs, except for the thinner nanowires. Moreover, the structure of the latter nanowires experiences important changes when the Li concentration increases up to the maximum Li atoms per cell. These results demonstrate that it is possible to simultaneously control the energy gap and the Young's modulus by tuning the Li concentration on the surface of the SiNWs and could help to understand the structural changes that the silicon nanowire arrays experience during the lithiation process in Li batteries. © 2016 Elsevier Ltd
Filiaciones:
Salazar, F.:
Inst Politecn Nacl, ESIME Culhuacan, Av Santa Ana 1000, Mexico City 04430, DF, Mexico
Perez, L. A.:
Univ Nacl Autonoma Mexico, Inst Fis, AP 20-364, Mexico City 01000, DF, Mexico
Cruz-Irisson, M.:
Inst Politecn Nacl, ESIME Culhuacan, Av Santa Ana 1000, Mexico City 04430, DF, Mexico
|