A High‐Performance Solution‐Processed Organic Photodetector for Near‐Infrared Sensing

• DOI: 10.1002/adma.201906027
• Publication Date: 2019-11-12T13:37:11Z
• Authors: Jianfei Huang; Jaewon Lee; Joachim Vollbrecht; Viktor V. Brus; Alana L. Dixon; David Xi Cao; Ziyue Zhu; Zhifang Du; Hengbin Wang; Kilwon Cho; Guillermo C. Bazan; Thuc‐Quyen Nguyen
• Keywords: Patient monitoring; Near Infrared; Specific detectivity; Infrared devices; bulk heterojunctions; Photons; Organic photodetector; Bulk heterojunction; Photodetectors; Organic photodiodes; Responsivity; high responsivity; 02 engineering and technology; Heart-rate monitoring; near-infrared; 7. Clean energy; Industrial research; Space charge limited currents; Heterojunctions; 0210 nano-technology; Photodiodes

Abstract Sensitive detection of near‐infrared (NIR) light enables many important applications in both research and industry. Current organic photodetectors suffer from low NIR sensitivity typically due to early absorption cutoff, responsivity, and/or large dark/noise current under bias. Herein, based on a novel ultranarrow‐bandgap nonfullerene acceptor, CO1‐4Cl, are presented, showcasing remarkable responsivity over 0.5 A W −1 the spectral region (920–960 nm), which is highest among photodiodes. By effectively delaying onset space charge limited suppressing shunt leakage current, optimized devices show specific detectivity around 10 12 Jones for up 1010 nm, close that commercial Si photodiode. The presented can also be integrated photoplethysmography real‐time heart‐rate monitoring, suggesting its potential practical applications.