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

Abstract

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.