Recent advances in the green processing of organic photovoltaic devices from nanoparticle dispersions

Abstract

Two decades of research have allowed organic solar cells to appear today as an alternative to hybrid and inorganic photovoltaic devices. However, several issues need to be addressed in order to facilitate their production on an industrial scale. Active layer processing is one of them. Indeed, high power conversion efficiency organic semiconductors are poorly soluble and require not only the use of toxic solvents but also moderate temperature (above 80 °C) processing for which the amount of generated vapors is critical. Recently, the use of conjugated polymer nanoparticle (NP) dispersions in water or alcohols has emerged as a possible solution to avoid toxic solvents. Recent studies have demonstrated that it is possible to finely tune the active-layer morphology using NPs and achieve high power conversion efficiencies. In this review, we aim at providing an up-to-date overview of this field by focusing on the different steps that make up the development of an organic photovoltaic device, from the preparation of nanoparticles to the characterization of the device. Finally, we provide perspectives for the future development of organic photovoltaic devices using a NP-based active layer.