Polythiophene Derivatives for Efficient All-Polymer Solar Cells

摘要

Polymerized small molecule acceptors have recently greatly facilitated thedevelopment of all-polymer solar cells (All-PSCs) with respect to the powerconversion efficiencies (PCEs). However, high-performance and low-costpolymer donors for All-PSCs are still lacking, limiting further large-scalemanufacturing of All-PSCs. Herein, this work designs and synthesizes a newthiophene derivative, FETVT, featuring vinyl-bridged fluorine andester-substituted monothiophene. Incorporation of FETVT into a polymeryields a high-performance polythiophene derivative PFETVT-T, which exhibitsdeep-lying HOMO level, suitable solution pre-aggregation ability, finely-tunedpolymer crystallinity, and appropriate thermodynamic miscibility with thepolymer acceptor L15. As a result, binary based on PFETVT-T achieves arecord PCE of 11.81% with agood stability, representing a breakthrough forpolythiophenes and their derivatives-based All-PSCs, which is alsosignificantly higher than that (1.92%) of All-PSCs based on its isomerizedanalog. Remarkably, PFETVT-T achieves an impressive PCE exceeding 16% viathe implementation of a ternary blend design. These findings offer a hopefulpathway toward attaining high-performance, stable, and cost-effective PSCs.