Molecular doping in Silicon Nanowires: an ab-initio study

We present ab-initio calculations based on density functional theory (DFT) of the effects on the electronic bands structure, total and projected density of states of surface molecular adsorption onto hexagonal cross-section silicon nanowires (SiNWs) grown along the direction. 〉〈111 Continuous miniaturization of microelectronic devices requires a corresponding reduction in feature size, and low-dimensional materials have become one of the most active research topics in recent years. In particular, SiNWs have attracted much attention due to their compatibility with conventional silicon-based integrated circuit technology allowing potential applications as building blocks in a variety of nano-scale devices such as field-effect transistors (FETs) [1], sensors [2], etc. Thus, advances in doping techniques are required that will allow the introduction of controlled amounts of dopants into nanowires (NWs) without degrading their electronic properties or morphology. Electrical doping for Si NWs has been achieved primarily through in situ doping, with the dopant introduced in the gaseous phase for incorporation during vapor-liquid-solid (VLS) growth, with metallic nanoparticles such as Au used as the catalytic growth seeds [3]. However, this in situ approach does not always give favorable results [4]. Enhanced surface doping during growth, for instance, competes with dopan