A Low-Cost 3D Spirobifluorene-Based Acceptor for High-Performance Ternary Organic Solar Cells
writer：Chunyan Liu, Nailiang Qiu,* Haonan Liu, Yuanyuan Kan, Yanna Sun, Ke Gao, Chenxi Li, and Yan Lu*
keywords：Organic solar cells, Acceptor
source：期刊
Issue time：2025年
The advantages of 3D materials as guest components of ternary organic solar
cells (TOSCs) are being realized, showing great potential in improving device
performance. However, the correlation between their distinctive 3D structure
and device performance remains largely unexplored. Herein, a 3D acceptor
named SF-HR is cost-effectively synthesized utilizing a twisted spirofluorene
core. SF-HR shows an edge-on oriented packing but not the disordered
aggregation as other 3D molecules. When introduced into D18:Y6 binary
system, SF-HR can induce more predominant face-on packing and finer
domain size in ternary blend, which facilitates exciton dissociation and
multi-direction charge transport. Besides, SF-HR exhibits complementary
absorption and cascaded energy levels with D18 and Y6, contributing to the
improvement of short-circuit current density (Jsc) and open-circuit voltage
(Voc), respectively. Accordingly, the optimized ternary device achieves higher
Voc of 0.893 V, Jsc of 27.13 mA cm?2, and fill factor (FF) of 77.8%, respectively,
than that of the host binary device, yielding an excellent efficiency of 18.85%.
This success demonstrates that the utilization of a crystalline 3D material as a
guest component represents a promising strategy for achieving
state-of-the-art OSCs, which is conducive to understanding the relationship
between 3D guest structure and device performance from a new perspective.