Laser-based Method for Sustainable Nanomanufacturing ☆

Silicon nanowires are promising for being used as building blocks for high-performance electronics and biomedical diagnostic devices due to their ultra-small bodies and high surface-to-volume ratios. However, the commonly used methods for manufacturing silicon nanowires involve using high temperature furnaces and a large amount of toxic gases. In addition, nanowires are often manufactured in a manner that requires many additional manufacturing processes in order to make functional devices. Here we present a single-step laser manufacturing method to synthesize silicon nanowires. In this method, nanowires are produced using a laser-guided chemical vapor deposition process, allowing for in-situ doping, catalyst-free nanowire growth, and control of the position, orientation, and length of nanowires. Importantly, the process requires a minimum heating power, of the order of mW, and a minimum amount of gas flow, of the order of a few sccm, since the nanowires are synthesized within the focused laser spot which has a diameter of about 250nm. In addition, the direct manufacturing of semiconductor nanowires on an insulating surface provides a platform ready for subsequent device fabrication.