Enhancing Light Harvesting in Organic Photovoltaics by Photonic Nanostructures

Organic solar cells have become a suitable photovoltaic technology thanks to their flexibility, scalability and light weight layout. They offer many advantages over the prevalent silicon industry, however, their efficiency is around 11%, still below the usual 20% on commercially available silicon solar panels [1], [2]. In this work, we propose an innovative method to increase light absorption on organic solar cells with photonic nanoimprinting technology. It consists on nanostructuring the active layer with a periodical structure that increases light diffraction within that layer. Diffraction favours light trapping due to total internal reflection, thus increasing the effective light harvesting of the solar cell. We chose soft lithography nanoimprinting because it can be easily applied as one extra manufacturing step without having to change the fabrication flow, or manufacturing time of current organic photovoltaics industry.