Achieving 20.80% Efficiency in Ternary Organic Solar Cells via Suppression of Static and Dynamic Disorder.

Abstract

Suppressing energetic disorder represents a critical pathway toward high-efficiency organic solar cells (OSCs). Herein, a ternary system is successfully developed to regulate the energetic disorder and enhance the photovoltaic performance of OSCs through strategic incorporation of a dimeric acceptor NVN into D18:L8-BO host. It is demonstrated that NVN incorporation simultaneously suppresses both static and dynamic disorder. Crucially, NVN-mediated suppression of dynamic disorder achieved through suppressing structural relaxation is identified as the dominant factor enhancing photoluminescence quantum yield (PLQY) and minimizing non-radiative energy loss. Furthermore, NVN optimizes the double-fibril network morphology (DFNM), induces graded vertical phase separation, and enhances molecular packing order. These morphological improvements reinforce structural regularity and mitigate static disorder. As a result, suppressed trap states, retrained energy loss, facilitated exciton dissociation, and improved charge transport are achieved in the ternary system. Owing to these synergistic effects, the D18:L8-BO:NVN ternary OSC achieves a remarkable power conversion efficiency (PCE) of 20.80% (certified 20.39%) with enhanced operational photostability. Overall, this work underscores the fundamental importance of energetic disorder control in achieving high-performance OSCs.