Synthesis and postgrowth doping of silicon nanowires

High-quality silicon nanowires (SiNWs) were synthesized via a thermal evaporation method without the use of catalysts. Scanning electron microscopy and transmission electron microscopy showed that SiNWs were long and straight crystalline silicon with an oxide sheath. Field effect transistors were fabricated to investigate the electrical transport properties. Devices on as-grown material were p-channel with channel mobilities 1–10cm2V−1s−1. Postgrowth vapor doping with bismuth converted these to n-channel behavior.