News Article
GaN Nanotubes
Researchers from the University of California Berkeley and the Lawrence Berkeley US National Laboratory have produced single crystal gallium nitride nanotubes of inner diameters ranging from 30nm to 200mm (Nature, April 10, 2003).
Researchers from the University of California Berkeley and the Lawrence Berkeley US National Laboratory have produced single crystal gallium nitride nanotubes of inner diameters ranging from 30nm to 200mm (Nature, April 10, 2003). The wall thicknesses are 5-50nm. The tubes are produced through epitaxial deposition on zinc oxide nanowires on sapphire wafers. The nanowires are later removed through thermal reduction and evaporation. The scientists believe the technique could be used with many other semiconductor systems.
Electrical and optical characteristics are comparable to those of high quality GaN epilayers grown on ZnO substrates and of GaN nanowires. Tube excitation spectra showed a slight blue shift compared to epilayers, being explained as due to a quantum confinement effect in the thin tube walls (as low as 5nm). GaN is one of the major materials used to create blue and green spectrum light emitting and laser diodes. Resistance is of the order 10MOhm at room temperature. This increases at lower temperatures.
Electrical and optical characteristics are comparable to those of high quality GaN epilayers grown on ZnO substrates and of GaN nanowires. Tube excitation spectra showed a slight blue shift compared to epilayers, being explained as due to a quantum confinement effect in the thin tube walls (as low as 5nm). GaN is one of the major materials used to create blue and green spectrum light emitting and laser diodes. Resistance is of the order 10MOhm at room temperature. This increases at lower temperatures.