Decahedral-shaped Au nanoparticles as plasmonic centers for high performance polymer solar cells

Abstract

The photon harvesting of the photoactive layer within a multilayered polymer solar cells (PSCs) greatly affects the output electric power of the devices. For PSCs, the device performance is very sensitive to the photoactive layer thickness. Therefore, how to enhance the light absorption of the photoactive film with fixed thickness is still a big challenge. Plasmonic enhancement induced by noble metal nanoparticles has been proved to be an effective way to enhance light trapping inside the photoactive film without increasing the thickness of film. By incorporating Au decahedra into the poly(3,4-ethylenedioxythiophene): poly(4-styrenesulfonate) (PEDOT:PSS) anode buffer layer, high performance plasmonic PSCs based on P3HT:PC60BM and PBDT-TS1:PC70BM were fabricated and the light response of the PSCs are greatly improved in a broadband wavelength, resulting in a remarkable enhancement in short-circuit current density. The calculation results of finite difference time domain (FDTD) confirm that the plasmonic effects induce enhancement in device performance. Upon optimization, the best power conversion efficiency (PCE) of the device based on P3HT:PC60BM and PBDT-TS1:PC70BM reaches 4.14% and 10.29%, respectively, among the best values reported in literature. These results can provide valuable guidelines for the design of metal nanostructures for organic photovoltaic applications.