WAPART - Water-based particulate approach to organic photovoltaics with controlled morphology

Research in organic solar cells have made tremendous progress in recent years, with reports of achieved power conversion efficiencies approaching 10% (comparable to the efficiency of amorphous silicon)[1]. This implies that organic solar cells is close to being capable of competing with already commercial technology, and thus to market entry.
The transfer to scalable processing methods however, presents new requirements and challenges where much of the knowledge and procedures developed in the laboratory is not applicable. The widespread use of harmful chlorinated and aromatic solvents presents a severe limitation for expanding the technology to production scale.
Recently, we have shown that it is possible to prepare working solar cells from aqueous dispersions of binary blend nano-particles, a route that opens up for a wealth of possibilities in terms of designing and restricting nano-structures[2]. The nano-structure dimensions can be effectively controlled by preparing nano-particles of acceptor/donor blends, with the particle dimensions setting the upper limit for blend demixing, improving the nano-structure lifetime as well. The active layer may also be formed by mixtures of acceptor and donor particles, with efficient structure control through particle size and shape. We will explore the use of such water-based inks for use in scalable, roll-to-roll coating of organic solar cells, suitable for industrial processing.
With this project, we will take the necessary steps to make the transfer of organic photovoltaics to a fully water-based process, providing access for industry to a commercial, environment friendly nano-technology, producing sustainable energy.