Precisely Controlling Polymer Acceptors with Weak Intramolecular Charge Transfer Effect and Superior Coplanarity for Efficient Indoor All‐Polymer Solar Cells with over 27% Efficiency

Abstract

Indoor photovoltaics (IPVs) are garnering increasing attention from both the academic and industrial communities due to the pressing demand of the ecosystem of Internet‐of‐Things. All‐polymer solar cells (all‐PSCs), emerging as a sub‐type of organic photovoltaics, with the merits of great film‐forming property, remarkable morphological and light stability, hold great promise to simultaneously achieve high efficiency and long‐term operation in IPV's application. However, the dearth of polymer acceptors with medium‐bandgap has impeded the rapid development of indoor all‐PSCs. Herein, we report a highly efficient medium‐bandgap polymer acceptor (PYFO‐V) through the synergistic effects of side chain engineering and linkage modulation and apply it for indoor all‐PSCs operation. As a result, the PM6:PYFO‐V‐based indoor all‐PSC yielded a highest efficiency of 27.1% under LED light conditions, marking the highest value for reported binary indoor all‐PSCs to date. More importantly, the blade coated devices using non‐halogenated solvent (o‐xylene) maintained an efficiency over 23%, demonstrating the potential for industry‐scale fabrication. Our work not only highlights the importance of fine‐tuning intramolecular charge transfer effect and intrachain coplanarity in developing high‐performance medium‐bandgap polymer acceptors, but also provides a highly efficient strategy for indoor all‐PSC application.This article is protected by copyright. All rights reserved