Gigantic absorption enhancement using nanostructured metal films: application to organic solar cells

Organic thin film solar cells have been researched as a low-cost alternative in solar energy technologies, but they usually have lower light harvesting efficiency. In this manuscript, a nanostructured metal film (NMF) fabricated based on self-assembly techniques is studied as a way to enhance the light absorbance in the absorbing layer, by the excitation of localized surface plasmon resonance. Finite-difference time-domain computations shows a 7-fold enhancement to the light absorbance in a 10 nm poly(3-hexylthiophene) (P3HT) layer on the NMF comparing to on flat metal. This result shows the possibility of an organic solar cell with a very thin absorbing layer and yet having a high efficiency. The NMF is also advantageous in its mass-producibility. Preliminary experimental results are also included.