A method of manufacturing silicon nano wires including forming microgrooves on a surface of a silicon substrate, forming a first doping layer doped with a first dopant on the silicon substrate and forming a second doping layer doped with a second dopant between the first doping layer and a surface of the silicon substrate, forming a metal layer on the silicon substrate, forming catalysts by heating the metal layer within the microgrooves of the silicon substrate and growing the nano wires between the catalysts and the silicon substrate using a thermal process.