Low temperature growth of boron nitride nanotubes on substrates

High growth temperatures (> 1100 degrees C), low production yield, and impurities have prevented research progress and applications of boron nitride nanotubes; (BNNTs) in the past 10 years. Here, we show that BNNTs can be grown on substrates at 600 degrees C. These BNNTs are constructed of high-order tubular structures and can be used without purification. Tunneling spectroscopy indicates that their band gap ranges from 4.4 to 4.9 eV.