Recent progress in organic solar cells (Part I material science)

During past several years, the photovoltaic performances of organic solar cells (OSCs) have achieved rapid progress with power conversion efficiencies (PCEs) over 18%, demonstrating a great practical application prospect. The development of material science including conjugated polymer donors, oligomer-like organic molecule donors, fused and nonfused ring acceptors, polymer acceptors, single-component organic solar cells and water/alcohol soluble interface materials are the key research topics in OSC field. Herein, the recent progress of these aspects is systematically summarized. Meanwhile, the current problems and future development are also discussed.