Large photocurrent generation in multiwall carbon nanotubes

The authors demonstrate the ability of multiwall carbon nanotubes to generate photocurrents in the near ultraviolet and visible spectral ranges using electrochemical photocurrent measurements. The photogenerated current depends on the excitation wavelength similar to that for single wall carbon nanotubes. Its intensity and modulation can be related to the carbon nanotubes morphology. The maximum photon-to-current conversion efficiency is approximately 7%, about 50 times higher than that reported for single wall carbon nanotubes. This result is of particular relevance for photovoltaic nanodevices and solar energy conversion applications. (c) 2006 American Institute of Physics.