Effect of shell thickness of gold-silica core-shell nanospheres embedded in an organic buffer matrix for plasmonic solar cells

The integration of metal nanoparticles in an organic buffer matrix for plasmonic organic solar cells (OSCs) has been explored as a route for improving the photovoltaic performance, with localized electromagnetic field enhancement around nanoparticles. We investigate the optical behavior of gold-silica core-shell nanospheres (Au@SiO2 NSs) with different shell thicknesses integrated into a 30 nm-thick poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) layer which is traditionally used as a buffer layer in OSCs. The morphology and size of the chemically synthesized Au@SiO2 NSs are determined by TEM, indicating that the average diameter of the Au core is about 50 nm, while the thickness of the dielectric shell can be adjusted to around 5 or 10 nm. The effect of Au@SiO2 NSs on the surrounding electromagnetic field in such a heterogeneous matrix and subsequent multilayers is examined using a numerical simulation based on a 3D-FDTD method. Furthermore, a broadband absorption enhancement in the films, which ...