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

## TL;DR

This paper introduces a new type of organic photodetector that detects weak light efficiently while minimizing dark current and can also detect light spot shapes.

## Contribution

A dual-functional photodetector with photon-regeneration gain and low dark current using integrated organic light-emitting diodes.

## Key findings

- The optimized PRM-OPD achieves a maximum external quantum efficiency of 2,484%.
- The device maintains a low dark current density of 10−8 A/cm2.
- The PRM-OPD can detect light spot shapes and operate in the near-infrared region with a narrowband response.

## Abstract

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 (EQE) 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 EQE of 2,484% and maintains a low dark current density (Jd) 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.