February 15, 2010
Four Inch Long, Semiconducting Triple-Walled Carbon Nanotubes
Direct growth of 100 mm (4 inch) semiconducting triple-walled carbon nanotubes (TWNTs) on Si substrates by chemical vapor deposition is reported by Tsinghua University Beijing, Peking University Beijing and CNano Technologies. By tailoring the temperature for a certain gas flow rate, a yield of nearly 90% of centimeter-long TWNTs is obtained. The TWNTs show an unprecedented structural homogeneity, in which each shell maintains a constant chiral index extending over a very large distance (>60 mm). The semiconducting TWNTs can be directly fabricated into field-effect transistors.