Fabrication of n-type mesoporous silicon nanowires by one-step etching.

In general, n-type mesoporous silicon nanowires (mp-SiNWs) are exclusively created by the two-step metal-assisted chemical etching (MACE). This work first reports that one-step MACE (in HF and AgNO3) is also capable of producing the n-type mp-SiNWs, and the developed formula is generally adapted to generate SiNWs by etching n-Si(100) with electrical resistivity over a range of 10(-3)-10(1) Ω·cm. Integrating the contribution of silicon intrinsic properties in the existing MACE mechanism explicitly accounts for the new findings and contradictions with previous studies. The as-generated mesoporous structures emit red light under laser excitation at room temperature. The red-color emission sensitively varies with temperature over a range of 16-300 K, attributed to a temperature-dependent photoluminescent mechanism.