Preparation of Photoluminescent Silicon Nanowires Based on Multicrystalline Silicon Wafers

Abstract

Single crystal silicon (sc-Si) wafers are widely used as the precursors to prepare silicon nanowires (SiNWs) by employing a silver-assisted chemical etching process. In this work, we obtained SiNWs arrays using multicrystalline silicon (mc-Si) wafers. Firstly, silver nanoparticles were deposited on the textured solar-grade mc-Si wafer by a galvanic displacement process; secondly, the SiNWs arrays were formed by a silver-assisted chemical etching process conducted in a HF-H2O2 aqueous solution. The etching process indicated that the growth of SiNWs is independent on the orientation of the Si wafer. TEM images showed that the SiNWs have rough and nanoporous structures on the top side along axial directions. The photoluminescence (PL) spectrum of SiNWs showed a broad visible emission centred around 700 nm, which is attributed to the emission properties of silicon nanocrystallites in SiNWs. This work may contribute to the development of SiNWs in application including optoelectronic devices, solar energy conversion devices, chemical sensors, and lithium secondary batteries, etc.