Plasmon-enhanced photocurrent in quasi-solid-state dye-sensitized solar cells by the inclusion of gold/silica core–shell nanoparticles in a TiO2 photoanode

Direct evidence of the effects of the localized surface plasmon resonance (LSPR) of gold nanoparticles (Au NPs) in TiO2 photoanodes on the performance enhancement in quasi-solid-state dye-sensitized solar cells (DSCs) is reported by comparing gold/silica core–shell nanoparticles (Au@SiO2 NPs) and hollow silica nanoparticles with the same shell size of the core–shell nanoparticles. The Au nanoparticles were shelled by a thin SiO2 layer to produce the core–shell structure, and the SiO2 hollow spheres were made by dissolving the Au cores of the gold/silica core–shell nanoparticles. Therefore, the size and morphology of the SiO2 hollow spheres were the same as the Au@SiO2 NPs. The energy conversion efficiency was improved nearly 36% upon incorporating the Au nanoparticles, mostly due to the increase in Jsc, while Voc and FF were unchanged. The improvement was mostly contributed by the LSPR of the Au@SiO2 NPs, whereas the other parameters, such as the electron lifetime and electron diffusion coefficient, were nearly unchanged. Therefore, LSPR is an effective tool in improving the photocurrent and consequently the performance of DSCs