Organic semiconductors are increasingly used in cost-efficient, lightweight and flexible devices such as thin-film transistors, light-emitting diodes and solar cells. In particular, third generation photovoltaics, based on such solution-processed semiconductors, promises to be the solution for near-future sustainable energy generation. All-organic photovoltaics (OPV) are recently attracting more and more interest due to remarkably high power conversion efficiencies (around 13%) recently obtained combined with good stability. Device optimization has naturally asked for the development of a rational understanding of the material structure-property relationships, of the photo-physical processes governing solar energy conversion and light emission, as well as of the transport properties. This knowledge, which crosses different device architectures and materials, is essential to further boost performances and to guide an intelligent material development. This symposium seeks to highlight the recent progress made in addressing the current challenges of the above-mentioned technologies with a special focus on: 1. Advances in materials design, emphasizing the importance of synthetic chemistry in tuning the material properties to obtain the desired functionality. 2. Developments on linking material processing, film morphology, local organization and optoelectronic properties. 3. Understanding of photophysical processes in the active layer (exciton/charge dynamics) or at materials interfaces at various length and time scales, accompanied by an in-depth computational analysis. 4. Insights in device function, with a special attention to device interfaces, fundamental processes therein and their stability. The interdisciplinary character of the topics, ranging from material science, physical chemistry, to device engineering will attract broad academic interest, with the final aim to advance our fundamental knowledge and close the gap of new generation semiconductor commercialization.

blend devices electronic structure energy generation microstructure morphology nanoscale photovoltaic Raman spectroscopy thin film