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.