Berlin 2018 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 39: Group IV (other than C): Si/Ge/SiC

HL 39.4: Vortrag

Donnerstag, 15. März 2018, 11:45–12:00, EW 015

Shell-Thickness Controlled Semiconductor-Metal Transition in Si-SiC Core-Shell Nanowires — •Michele Amato — Université Paris-Sud, Orsay, France

Today Si nanowires (NWs) represent a viable solution to realize high-performance sensors due their potential for fabrication into high density nanoscale devices [1]. The large surface-to-volume ratio and the possibility to tune their properties at growth time controlling the composition, crystal orientation, and diameter make Si NWs bound to outperform any other conventional alternative in a large class of sensing environments [1]. On the other hand, because of its excellent chemical and mechanical stability, high hardness and low density it is widespread belief that SiC is a much better biocompatible material than Si. The combination of Si and SiC in a nanostructure, as shown by recent experiments [2], could lead therefore to a material with the smart properties of Si and the biocompatibility of carbon-based systems. We study Si-SiC core-shell NWs by means of electronic structure first-principles calculations [3]. We show that the strain induced by the growth of a lattice mismatched SiC shell can drive a semiconductor-metal transition. Core-shell nanowires with thicker cores, however, remain semiconducting even when four SiC monolayers are grown, paving the way to versatile, biocompatible nanowire-based sensors.

[1] M. Amato and R. Rurali, Prog. Surf. Sci. 91, 1-28 (2016) [2] L. Latu-Romain and M. Ollivier, J. Phys. D, 47, 203001 (2014) [3] M. Amato and R. Rurali, Nano Lett. 15, 3425 (2015)