Properties of Si nanowires as a function of their growth conditions

Silicon nanowires physical properties strongly depend on their growth conditions, as already assessed. We report on the electrical properties of nanowires (NWs) grown by the vapor–liquid–solid (VLS) mechanism, one of the most established for NW growth, and by the more recent metal-assisted wet chemical etching (MaCE). Wet etching growth process promises to be an industrial advantageous way for growing Si NWs, because of its cheapness, fastness, relative easiness. The electronic level scheme in VLS grown, boron (B)- and phosphorus (P)-doped NWs has been experimentally investigated. We have demonstrated that the doping impurities induce the same shallow levels as in bulk silicon. The presence of two donor levels in the lower half-bandgap is also revealed, which has been successfully related to VLS growth details. We report, also, on the first results on the physical properties of Si NW arrays grown by MaCE, and compare them to those of VLS grown Si NWs.