Abstract: Dimeric acceptors are intrinsically advantageous in terms of device stability. However, they generally exhibit moderate power conversion efficiencies (PCEs) and are prone to suboptimal nanoscale morphology, which collectively impede their development in organic solar cells. Herein, we present two asymmetric dimeric acceptors, CH8-15 and CH8-16, which were rationally designed via the asymmetric endgroup functionalization of a two-dimensional extended dimer platform. By precisely modulating the steric configurations, CH8-16, which exists as a mixture of three configurational isomers, displays a reduced overall dipole moment yet demonstrates substantially enhanced molecular crystallinity and packing order relative to CH8-15. The PM6:CH8-16 binary device delivers a PCE of 17.44%, surpassing that of the PM6: CH8-15-based device (16.86%), with the improvement primarily originating from an enhanced fill factor. More significantly, the incorporation of CH8-16 as a third component into the PM6:L8-BO host system affords a ternary device achieving an outstanding PCE of 19.73%, accompanied by superior exciton dynamics and optimized morphology. Furthermore, the blend of CH8-16 and L8-BO substantially enhances both thermal and photo-stability of the corresponding devices. This work establishes that the asymmetric end-group strategy offers an effective molecular design path for developing efficient dimeric acceptors.

Cite: Wang P. , Yang J. , Bai Y. , Rakitin O.A. , Kan B.
Asymmetric end-group strategy for three-dimensional dimeric acceptors enabling efficient organic solar cells
Science China Materials. 2026. DOI: 10.1007/s40843-026-4453-8 WOS Scopus OpenAlex

Dates:

Submitted:	Jul 1, 2026
Accepted:	Aug 9, 2026
Published online:	Oct 23, 2026

Identifiers:

≡ Web of science:	WOS:001918337300001
≡ Scopus:	2-s2.0-105055110633
≡ OpenAlex:	W7224383151

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