Plasmon-induced slow aging of exciton generation and dissociation for stable organic solar cells

Fast degradation is a major issue with organic photovoltaics (OPVs). Integrating plasmonics with OPVs has improved their efficiency; however, the stability effects are unknown. We demonstrate that plasmonic effects can improve the lifetime and efficiency. The aging effects on charge carrier generation and transport are investigated. Confocal time-resolved photoluminescence of Au nanoparticle (NP) doped polymer blend was performed to understand the plasmonic effects on excited-state dynamics. Hot exciton generation is observed directly at the Au-NP surface, which contributed to achieving a nearly perfect exciton dissociation yield. We found that slow aging of the plasmonic effect and the hot exciton contribution are the reasons for the improved lifetimes of plasmon-enhanced OPVs. This work opens up a new direction for improving the stability of OPVs and enhancing the application of plasmonics. (C) 2016 Optical Society of America