Colloidal InSb Quantum Dots/Organic Integrated Bulk Heterojunction for Fast and Sensitive Near‐Infrared Photodetectors

It remains urgent to integrate conductive InSb colloidal quantum dots (CQDs) for sensitive and fast near‐infrared (NIR) photodetection applications. Herein, nanocrystallized InSb CQDs (<12 nm in diameter) have been successfully obtained via hot‐injection procedure, and demonstrated a very narrow absorption peak centered at 1406 nm with a full width at half maximum (FWHM) of 10.3 nm and a broader absorption peak at 1702 nm, indicating strong quantum‐confined effect. After integrating these InSb CQDs with [6,6]‐phenyl C61‐butyric acid methyl ester (PCBM) and polymeric triphenyldiamine (poly(N,N′‐diphenylben‐zidine diphenylether), poly‐TPD) bulk junction, the obtained Si/SiO2/InSb CQDs:PCBM:poly‐TPD/Ag photodetector has reached long‐wavelength response up to 1400 nm, fast response time (<80 ms), and superior on/off ratio. In specific, charge carriers can be effectively transported due to favorable energy alignment and interpenetrating network formed in the inorganic/organic blend films. The work provides a new strategy to synthesize high‐quality InSb CQD and reveal its starting point toward low‐cost, practical, and sensitive next‐generation NIR detection.