Enhancement of silicon nanowire opto-electric properties by combining acid vapor etching and lithium pore-filling

Highly Efficient Silicon Nanowire Surface Passivation by Bismuth Nano-Coating for Multifunctional Bi@SiNWs Heterostructures

“…(2) Bi treatment leads to a reduction in the deep trap density and quenches a large part of the silicon dangling bands generated during the etching process for SiNW formation. Thus, a passivation of the non-radiative centers occurs via the substitution of the unstable Si–H bands by the stable Bi–O–Si bands, Bi–OH, and other carbon-based functional groups, as revealed from the FTIR analysis [ 13 ]. (3) A possible increase in the density and/or creation of new radiative centers under the photo excitation of the charge carrier generated from the Bi deposits.…”

“…Amri et al show that the passivation of SiNWs with lithium not only improves the luminescence but also ensure a long PL lifetime. [ 13 ]. Herein, the Bi coating on SiNWs achieves an interesting PL enhancement, reaching a factor of nine-fold, as seen above, as well as the stabilization of the NW structure, which is very interesting and promising for nanoscale optoelectronic devices.…”

“…To address these problems, one of the most effective strategies is SiNW surface passivation through loading metal nanoparticles (MNPs), resulting in dangling bond saturation and the formation of a stable passivation thick layer. In this context, many attempts at passivation have been reported in the literature, and several nanoscale metals have been anchored on SiNWs—e.g., Au; Ag; Pt; Pd; Cu; Li; and even bimetal NPs, e.g., Au-Ag, Au-Pd, and Pd-Ni [ 2 , 3 , 5 , 9 , 10 , 11 , 12 , 13 , 14 ].…”

“…For instance, photoluminescence (PL) enhancements with a factor of four and eight were recently reported for AgNPs-SiNW and AuNPs-SiNW heterostructures, respectively [ 10 , 15 ]. Amri et al reported that the electrochemical deposition of Li on SiNW layers is responsible for the improvement of the minority carrier lifetime and the decrease in the reflectivity [ 13 ]. Moreover, Ghosh et al demonstrate multifunctional AgNP-decorated SiNWs for sensing, photocatalysis, and light emission [ 9 ].…”

“…Other reports have highlighted the superior passivation of vertically aligned Si nanorods by a SiO 2 -multiwall carbon nanotube (SiO 2 /MWCNT) multishell [ 17 ]. Different techniques can be employed for the deposition of MNPs, including electroless deposition via a chemical solution [ 9 , 12 , 13 ], pulsed laser ablation [ 11 ], drop-casting [ 16 ], thermal evaporation [ 5 , 18 ], and more. The later technique is recommended and is one of the simplest and economical methods, enabling easy material anchoring with good properties and reduced surface damage [ 19 , 20 , 21 ].…”