Fabrication of a light trapping system for organic solar cells

Organic photovoltaic cells (OPV) are among the most promising systems for energy extraction and conversion from renewable energy sources. However, major problem to be solved before industrial production could become economically viable is represented by their still low conversion efficiency. The organic solar cell architectures are presently the result of a compromise between achieving complete light absorption using active layers that are thicker than the optical absorption length and achieving efficient charge collection at the electrodes which is favoured in thinner layers. We present a concept and its experimental demonstration that would solve efficiently the above trade-off problem by making use of a new type of light trapping elements. The simple fabrication scheme, based on a self-aligned UV exposure process, suggests its potential up-scalability to large systems, at low production cost.