Y6 derivatives for near-infrared organic photodetectors with enhanced specific detectivity

Abstract

Recently, the advancement of non-fullerene acceptors (NFAs) for near-infrared (NIR) organic photodetectors (OPDs) has garnered significant attention due to their superior NIR light absorption characteristics. Notably, the attractive properties of Y6 and its derivatives, such as enhanced π-π stacking and stronger NIR absorption, can enhance the performance of optical photodetectors due to improved intermolecular stacking, optical absorption, and charge transfer properties. Herein, we designed and synthesized two fused small molecules, BTP-eC9-4F and BTP-eC9-4Cl, for efficient bulk heterojunction NIR OPDs. The OPDs with these NFAs exhibited excellent performance, extending their spectral response from the visible (Vis) to the NIR region. Specifically, devices with BTP-eC9-4Cl exhibited a specific detectivity (D∗) of 8.49 $\times$ 10¹⁰ Jones at 850 nm under a -2V bias, attributed to its optimized molecular design, which leads to reduced dark current density with relative deep energy improved morphology, its potential for high-performance NIR OPD applications.