Infrared visualization based on quantum dot upconversion photodetector using perovskite emitter

An upconversion device uses a methodology for direct infrared imaging, but the performance is limited by the inefficient carrier transmission between infrared detecting and emitting layers. Herein, we developed an upconversion infrared imaging device by integrating infrared quantum dots and a perovskite quantum well emitter. The energy level of the perovskite quantum well aligns well with the infrared quantum dot, leading to an effective carrier transition between them, generating a photon conversion efficiency of over 10% and a high on-off ratio of 45.5. The device shows a resolution of 11 μm, 3-fold higher than the best value achieved for solution-processed infrared upconversion devices. Furthermore, based on solution-phase ligand exchange, a large-area homogeneous 3 × 3 cm upconversion device is fabricated. The large-area device shows an estimated pixel scale of over 7 million pixels, enabling it to be used for direct infrared visualization.