Ternary organic photovoltaic solar cells based on quinoxaline polymers with an acceptor – Acceptor backbone

Abstract

Incorporating a ternary system in organic solar cells (OSCs) is considered a promising strategy for enhancing their performance. In this study, a PDTBT-Qx polymer was designed and synthesized, incorporating quinoxaline with long alkyl side chains as one unit and DTBT as the other. The incorporation of PDTBT-Qx as a third component into the PM6:L8-BO system improved donor–acceptor compatibility, facilitated the phase separation, and promoted crystallization within the blend. When the addition of 10 wt% PDTBT-Qx, the ternary device achieved optimal photovoltaic performance, with a short-circuit current density (J_SC) of 23.61 mA cm⁻², a fill factor (FF) of 69.71 %, and a power conversion efficiency (PCE) of 13.83 %. This is because the inclusion of PDTBT-Qx enhances solar energy utilization owing to complementary light absorption and reduced charge recombination losses. Meanwhile, the dissociation of excitons was facilitated, and the charge collection was promoted. This study demonstrates the potential of quinoxaline-based materials, including broad-spectrum absorption and low recombination energy, which makes it a promising third component candidate for high-performance ternary OSCs.