Physical Mechanisms on Plasmon-Enhanced Organic Solar Cells

An organic solar cell is regarded as one of the emerging and potential alternatives for solar cells, due to its low cost and high photoelectric conversion efficiency. Here, using the plasmon-enhanced method, the electric field of the polythiophene/indene-C-60 bisadduct (PT:IC(60)BA) donor-acceptor system as the photoactive molecular layer is significantly enhanced up to the order of 104 at around 475 nm. Besides, the surface plasmon thermal effect is calculated based on the coupling model of a nanoparticle dimer with a Ag film, where the molecular layer is in the nanocavity between the dimer and the film. The band gap and open-circuit voltage decrease with the increase of temperature. The electron-hole generation rate is enhanced up to 1.4 x 10(3), and photocurrent can be enhanced around 230 times by surface plasmon resonance. Our results provide theoretical support for plasmonenhanced organic solar cells.