Viologen phosphoric acid salt modified <scp>PEDOT</scp> : <scp>PSS</scp> for high‐performance <scp>3D</scp> perovskite photodetectors

Abstract Perovskite photodetectors (ePDs) have shown significant promise for applications in imaging and optical communications due to their excellent optoelectronic properties. Dark current density ( J d ) plays a crucial role in determining the performance of 3D PePDs based on poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). Herein, a novel viologen derivative, 1‐allyl‐1′‐(2‐phosphonoethyl)‐viologen (APV), is introduced into PEDOT:PSS to improve the crystalline quality of the perovskite film and effectively suppress dark current. Consequently, the optimized 3D PePD achieves an ultra‐low J d of 5.75 × 10 −7 mA cm −2 at −0.5 V and a maximum specific detectivity of 2.08 × 10 13 Jones at 705 nm, positioning it among the top high‐performance 3D PePDs for visible photodetection. Furthermore, the optimized PePD exhibits a fast response time of 256 ns and a large bandwidth of 1.5 MHz. Upon successful integration into an optical wireless communication (OWC) system as the signal receiver, it demonstrates a data rate of up to 12.5 Mbps with minimal distortion. We believe that APV modification provides a universal strategy to realize sensitive PePDs, potentially revolutionizing the applications of OWC and imaging. image