Affiliation:
1. Department of Physics and Centre for Processable Electronics Imperial College London Blackett Laboratory London SW7 2AZ UK
2. Physical Sciences and Engineering Division (PSE) King Abdullah University of Science and Technology (KAUST) Thuwal 23955‐6900 Saudi Arabia
3. Department of Physics The Chinese University of Hong Kong Sha Tin, NT Hong Kong 999077 China
4. Department of Chemistry and Centre for Processable Electronics Imperial College London Molecular Sciences Research Hub White City Campus London W12 0BZ UK
Abstract
AbstractDespite major advances in efficiency, the operational stability of organic photovoltaic (OPV) devices remains poor. Therefore, understanding the degradation mechanisms and identifying potential solutions to improve device stability is critical to enabling the widespread commercialization of OPVs. Herein, simple filtration of the PBDB‐T:ITIC photoactive layer (PAL) solution prior to film deposition is demonstrated to enhance OPV device operational stability without compromising initial device performance. The effect of filtration, a commonly used but poorly understood OPV fabrication step, is investigated using a range of chemical, structural, and optoelectronic methods, on solutions and films. Filtration is found to remove large aggregates from solution without disrupting nanoscale preaggregation, resulting in enhanced acceptor ordering in PBDB‐T:ITIC thin films, significantly improving morphological stability and photostability. This simple and facile method is confirmed to be a general strategy that also works for other PBDB‐T‐containing OPV blends, including Y6‐based systems, and highlights how subtle changes in morphology can result in dramatic differences in operational stability.
Funder
Engineering and Physical Sciences Research Council
National Natural Science Foundation of China