Well-aligned silicon nanowires with controlled diameter and doping concentration are successfully synthesized using the electric-field-assembly technology in a low pressure chemical vapor deposition system. By an appropriate combination of high-k dielectric and mechanical stress, aligned silicon nanowires show significant potential for applications in junctionless field-effect transistors, nonvolatile memories and biosensors. In addition, carbon-coated heavily-doped n-type SiNWs are demonstrated to be a promising lithium battery anode due to their high power density and long cycle life.