A method of synthesizing silicon wires generally includes the steps of: providing a substrate; forming a copper catalyst particle layer on a top surface of the substrate; heating the reactive device at a temperature of above 450° C. in a flowing protective gas; and introducing a mixture of a protective gas and a silicon-based reactive gas at a temperature of above 450° C. at a pressure of below 700 Torr, thereby forming the silicon wires on the substrate.