This additional HF dip resulted in dissolution of the upper part of the SiNWs. The length of the remaining SiNWs was only the one fourth of their original length. However, even if the SiNW length was significantly smaller, the PL intensity was increased by more than one order of magnitude. To our opinion, PL in this case comes mainly from the mesoporous Si layer underneath the SiNWs. The mean size of NCs in this layer was initially large, while it was reduced by HF/piranha/HF treatments. The peak position is mainly determined by the mean size of the NCs of this layer. Consequently, there is no direct comparison of this spectrum with the three previous spectra. Conclusion The structure, morphology, and
light-emitting properties of SiNWs fabricated Ilomastat ic50 by a single-step selleckchem MACE process on p+ Si were investigated for samples subjected to different chemical treatments after the SiNW formation. The investigation of the structure and morphology of the nanowires revealed that their whole volume was porous, this being also confirmed by the fact that after successive HF and
piranha treatments, almost all the upper part of the vertical nanowires was fully dissolved in the chemical solution, leaving only their less porous nanowire base www.selleckchem.com/products/pnd-1186-vs-4718.html intact. Hydrogen-passivated SiNWs showed shifted PL spectra compared to the oxidized ones, due to defects at the interface of the Si nanocrystals with the SiO2 shell that are involved in the PL recombination mechanism. All the obtained results concerning light emission and structural characteristics of the SiNWs were consistent with those expected from assemblies of Si nanocrystals with a size dispersion and different surface passivation. Acknowledgment This work was supported by the EU Network of Excellence Nanofunction through the EU Seventh
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