Rational Regulation of the Molecular Aggregation Enables A Facile Blade-Coating Process of Large-area All-Polymer Solar Cells with Record Efficiency

Abstract

Developing robust materials is very critical and faces a big challenge for high-performance large-area all-polymer solar cells (all-PSCs) by printing methods. Herein, the authors combine the advantages of the terpolymerization strategy with the non-conjugated backbone strategy to regulate the molecular aggregation rationally during the film-forming printing process, facilitating a facile printing process for large-area all-PSCs. A series of terpolymer acceptors PYSe-Clx (x = 0, 10, 20, and 30) is also developed, which can effectively fine-tune the morphology and photoelectric properties of the active layer. The PBDB-T: PYSe-Cl20-based all-PSC delivers a significantly improved power cconversion efficiency (PCE) than the one with PBDB-T: PYSe (14.21% vs 12.45%). By addition of a small amount of non-conjugated polymer acceptor PTClo-Y, the ternary all-PSC reaches a PCE of 15.26%. More importantly, the regulation of molecular aggregation enables a facile blade-coating process of the large-area device. A record PCE of 13.81% for large-area devices (1.21 cm(2)) is obtained, which is the highest value for large-area all-PSCs fabricated by blade-coating. The environmentally friendly solvent processed large-area device also obtains an excellent performance of 13.21%. This work provides a simple and effective molecular design strategy of robust materials for high-performance large-area all-PSCs by a printing process.