Versatile Self‐Assembled Monolayer Material Enables Efficient Organic Photovoltaic Devices and Modules

Abstract Efficient and stable hole transport layer (HTL) is an important component of organic photovoltaics (OPV). Herein, a novel self‐assembled monolayer material of 4PADCB (short for (4‐(7H‐dibenzo[c,g]carbazol‐7‐yl)butyl)phosphonic acid) as HTL for non‐fullerene (NF) OPV is reported. Compared to the widely used PEDOT:PSS HTL, the usage of 4PADCB not only enhances photon incident and charge generation but also effectively improves the morphology of the upper active layer, promotes molecular packing, and balances the carrier transport within active layer. As a result, the single‐junction binary D18:L8BO OPV, employing 4PADCB as HTL, achieves a high‐power conversion efficiency (PCE) of 19.02% with excellent storage stability. Furthermore, a 19.3 cm 2 OPV module comprising seven sub‐cells demonstrates a maximum PCE of 15.44%, which is the highest value of reported efficiency for large‐area binary OPV modules. Meanwhile, the module is the first demonstration of an OPV module based on self‐assembled monolayer material. This work underscores the substantial potential for the application of 4PADCB in efficient NF OPV devices and high‐throughput large‐area modules.