Fullerene-Free Organic Solar Cells with Efficiency over 12% Based on EDTA-ZnO Hybrid Cathode Interlayer

Developments in fullerene-free acceptors are driven by the need to find alternative ones that overcome the poor absorption property, limited band gap adjustability, and high synthetic cost of fullerene acceptors. Through chemical structure optimization, the power conversion efficiency (PCE) can be further improved to 9.6° by employing ITIC-Th acceptor. Subsequently, many efforts have focused on the synthesis of fullerene-free acceptors and corresponding matching donors, pushing efficiency to 9-11°. Recently, device efficiency of 12° can be achieved by energy level modulation of fullerene-free acceptors..