Addressing Responsivity‐Noise Trade‐Off by Van der Waals Multilayer Two‐Phase Heterojunction for Large LDR Organic Photodetectors

Abstract

AbstractOne of the main challenges most organic photodiodes (OPDs) facing is to overcome the traditional trade‐off between ultralow dark current and high responsivity (R) in existing research. Here, van der Waals multilayer OPD based on water transfer printing method, termed hybrid bulk‐heterojunction (BHJ)/planar‐heterojunction (PHJ) (B‐PHJ) framework, is constructed making certain the high‐quality interface and novel two‐phase energy band alignment between the active and barrier layer with noise suppression and photovoltaic complement simultaneously. The prepared OPD exhibits the combined advantages of ultralow dark current (0.2 nA cm−2 at −1 V) and high responsivity (0.49 A W−1 at 850 nm). As a result, these superimposed effects enable the device to feature a superior liner dynamic range (LDR) of 210 dB and a specific detectivity of 1014 Jones to address the conventional responsivity‐noise trade‐off. The results reveal that the balance dynamics of charge transfer and charge blocking in van der Waals hybrid two‐phase framework OPD, may inspire the development of next OPDs. Finally, its diverse practical application potential is demonstrated through long‐distance misaligned photoplethysmography (PPG) measurement.