Dual‐Band Organic Photodetectors for Dual‐Channel Optical Communications

• Published in: Laser & photonics reviews 2022-07, Vol.16 (7), p.n/a
• Main Authors: Lan, Zhaojue, Lau, Ying Suet, Cai, Linfeng, Han, Jiayin, Suen, Chun Wai, Zhu, Furong
• Format: Article
• Language: English
• Subjects: Bias; bias‐switchable; dual‐band; heterojunctions; Near infrared radiation; near‐infrared; Optical communication; organic photodetectors; Photometers
• ISSN: 1863-8880; 1863-8899
• DOI: 10.1002/lpor.202100602

The dual‐band organic photodetectors (OPDs) detect incoming light selectively in two different bands. This work demonstrates a bias‐switchable dual‐band OPD, achieving a fast‐switching speed of over 1000 times per second and a −3 dB cutoff frequency of > 100 kHz for high‐speed optical communications in two distinct bands, e.g., near‐infrared (NIR) and visible light. Visible‐blind NIR detection with a high responsivity of 435 mA W–1 is realized for the OPDs operated under a small reverse bias of −1.0 V. NIR‐blind visible light detection with a responsivity of 325 mA W–1 is obtained for the OPDs operated under a low forward bias of 1.0 V. Dual‐channel NIR/visible optical communication technique has been demonstrated, providing an opportunity for a plethora of applications in information electronics and the Internet‐of‐Things. The bias‐switchable crosstalk‐free dual‐band organic photodetectors (OPDs) have a fast‐switching speed of over 1000 times per second and a −3 dB cutoff frequency of >100 kHz for detection in two distinct bands, e.g., near‐infrared and visible light. The dual‐band OPDs provide an opportunity for a plethora of applications in optical communications, security monitoring, self‐aligned image sensing, and artificial intelligence.