Kinked silicon nanowires prepared by two-step MACE process: Synthesis strategies and luminescent properties

Abstract

We report the controlled fabrication of kinked silicon nanowires (SiNWs) using ethanol mixed facile two-step metal-assisted chemical etching (MACE) method. Accordingly, the kink angle, straight path, and the number of kinks in kinked SiNWs are controlled by varying the volume of ethanol and etching time in high concentrated plating and etching solutions. The silver nanoparticles (AgNPs) during the etching need to travel a critical length (≥1.5 μm) in a vertical direction before the kink formation. The presence of ethanol in etching solution affects the availability of H2O2 and HF at Si/Ag interface and has a major effect on the etching process. The room temperature photoluminescence (PL) emission of kinked SiNWs is tuned from the red region to the blue region by controlling the amount of ethanol in the etching solution. The temporal behaviour of the PL data of the kinked SiNWs has been provided to understand in depth the optical transition processes.