C60 sensitization of a photorefractive polymer

The fullerene molecule C60 is shown to act as a useful sensitizer of a recently discovered photorefractive polymer. Measurements of the steady-state diffraction efficiency, grating growth rate, and other photorefractive properties are presented as a function of C60 concentration, writing intensity, and applied electric field. The dc photoconductivity, grating growth rate, and steady-state diffraction efficiency all increase by as much as a factor of 20 upon doping with up to 0.2 wt % C60. The sensitization appears to result from a small increase in the carrier generation efficiency and a larger increase in the useful optical absorption at the operating wavelength, 647 nm.