A continuous process for Si nanowires with prescribed lengths

Abstract

A simple top–down approach for the continuous mass preparation of single crystalline silicon nanowires (SiNWs) with controlled lengths was developed. The approach is based on periodic pulsing of anodic bias during gold-assisted chemical etching of a silicon substrate and subsequent ultrasonic treatment of the resulting porosity-patterned SiNWs for selective breakage of nanowires at the porous segments, and allows us to overcome some of the drawbacks in conventional bottom–up methods for SiNW growth.