A Novel Dual-Functional Photomultiplication-Type Organic Photodetector with Photon-Regeneration Gain by Integrated Organic Light-Emitting Diodes

Because of their outstanding weak light detection ability, multiplication-type photodetectors have great application prospects in fields such as environmental detection, biological science, and night vision imaging. Traditional photomultiplication-type organic photodetectors (PM-OPDs) usually achieve a large external quantum efficiency (<i>EQE</i>) through the mechanism of interfacial trap-assisted charge tunneling injection but inevitably produce a large dark current. Here, we demonstrate a novel dual-function photon-regeneration multiplication-type organic photodetector (PRM-OPD) with photocurrent gain by absorbing additional photons generated by an integrated organic light-emitting diode unit. The optimized PRM-OPD exhibits a maximum <i>EQE</i> of 2,484% and maintains a low dark current density (<i>J_d</i> ) of only 10^-8 A/cm². More importantly, the resulting PRM-OPD can not only exhibit efficient detection performance but also directly detect the shape of the light spot, showing a dual-function working mode. Furthermore, by combining optical resonant microcavities, the response spectrum is successfully extended to the near-infrared region and a narrowband PRM-OPD with excellent performance is obtained. This designed device structure provides a new idea for the development of high-performance PM-OPDs.