Organic Upconversion Imager With Switchable Photomultiplication Response and Large‐Area Optical Readout

ABSTRACT Light detection and imaging are the foundation of optoelectronic technology. By integrating an organic photomultiplication (PM) photodetector with broadband and narrowband response capabilities into an organic light‐emitting diode (OLED) unit, an upconversion imager featuring a switchable PM response and large‐area optical readout has been realized. The organic upconversion imager exhibits a broadband photoresponse covering 400–1000 nm with an external quantum efficiency (EQE) of over 500% under bottom illumination and a narrowband photoresponse peaked at 800 nm under top illumination, featuring a full width at half maximum (FWHM) of ∼200 nm and a peak EQE of 383%. Additionally, the organic upconversion imager demonstrates excellent performance, directly converting incident near‐infrared (NIR) patterns into visible images over its active area of ∼2.5 cm 2 . The unique optoelectronic properties of the imager enable several application demonstrations, thus showcasing its distinctive electro‐optical dual‐readout ability and significant potential for anti‐interference detection and imaging.