Colloidal Quantum-Dot Heterojunction Imagers for Room-Temperature Thermal Imaging

Room-temperature operation or high-operation temperature (HOT) is essential for mid-wave infrared (MWIR) optoelectronics devices providing low-cost and compact systems for numerous applications. Colloidal quantum dots (CQDs) have emerged as a rising candidate to enable photodetectors to operate at HOT or room temperature and develop the next-generation infrared focal plane array (FPA) imagers. Here, band-engineered heterojunctions are demonstrated to suppress dark current with well-passivated mercury telluride (HgTe) CQDs enabling room-temperature MWIR imaging by single-pixel scanning and 640 × 512 FPA sensitive thermal imaging above 250 K. As a result, the room-temperature detectivity reaches as high as 1.26 × 10¹⁰ Jones, and the noise equivalent temperature difference (NETD) is as good as 25 mK up to 200 K.