Bimolecular recombination on carbon nanotubes

Abstract
By using a suspension of single-walled carbon nanotubes in an applied electric field and measuring transient photoinduced currents the problem of contacting nanotubes in charge transport studies is circumvented; basic electronic transport properties are thus studied. It is observed that the peak photocurrent excited by a mode-locked laser pulse has a sublinear dependence on light intensity. Careful measurement of these phototransients has allowed a fit of the intensity dependence of the peak photocurrent to a bimolecular recombination model developed for the one-dimensional semiconductor that the nanotubes represent. Application of the model allows the determination of some microscopic transport properties. This has been done as concentration, electric field and excitation wavelength are varied.