Exciton-plasmon coupling mediated photorefractivity in gold-nanoparticle- and quantum-dot-dispersed polymers

In this paper, we report on the enhanced photorefractivity induced by the exciton-plasmon coupling in type-II CdSe/CdTe quantum-dot (QD) and gold-nanoparticle (NP)-doped polymeric nanocomposites (NCs). The new NCs exhibit a nearly 110% increase in the refractive-index grating construction speed and a 100% enhancement in the two-beam coupling gain coefficient compared with those of QD-sensitized samples at moderate biases. These features are achieved by the exciton-plasmon coupling between QDs and Au NPs, which leads to not only an enhanced charge separation process but also a reduced recombination probability of free carriers during the charge transport.