Sensitive near-infrared circularly polarized light detection via non-fullerene acceptor blends
Li Wan, Rui Zhang, Eunkyung Cho, Hongxiang Li, Veaceslav Coropceanu, Jean‐Luc Brédas, Feng Gao
Abstract
Abstract Circularly polarized light (CPL) is widely used for various applications in sensing and imaging 1–3 . An ongoing challenge is to realize high-quality CPL detection using chiral organic semiconductors, especially in the near-infrared (NIR) region 4 . Chiral molecules tend to rely on twisted stereogenic moieties; however, conventional approaches to reduce the bandgap of organic semiconductors are based on the use of co-planar backbones that commonly lead to molecular symmetries preventing chirality. Here we report a widely applicable strategy to directly induce chiroptical activity in planar non-fullerene acceptors 5–7 , which are widely used for high-performance organic photovoltaics and provide a wealth of opportunities to fill the spectral gap of CPL detection in the NIR regime. We demonstrate proof-of-concept circularly polarized organic photodiodes using chiroptically active non-fullerene acceptor blends, which exhibit strong circular dichroism and hence great sensitivity to CPL in the NIR region. Importantly, this strategy is found to be effective in a wide series of state-of-the-art non-fullerene acceptor families including ITIC 5 , o -IDTBR 6 and Y6 analogues 7 , which substantially broadens the range of materials applicable to NIR CPL detection.