Local Dipole Modulation Toward High Fill Factor in Organic Solar Cells.
Adv Mater
; 36(41): e2408858, 2024 Oct.
Article
en En
| MEDLINE
| ID: mdl-39132752
ABSTRACT
Dipole moment arrangement in organic semiconductors plays a critical role in affecting the intermolecular packing, determining optoelectronic properties and device performance. Here, to get the desired fill factor (FF) values in organic solar cells (OSCs), the local dipole of non-fullerene acceptors (NFAs) is modulated by changing the molecular asymmetries. Two NFAs, AA-1 and AA-2 are designed and synthesized, which have different substitutions of alkyl and alkoxyl groups. The unidirectional asymmetry in AA-2 creates distinct local dipoles, while the bidirectional asymmetry in AA-1 mitigates dipole variation. Despite the minimal impact on monomolecular properties, the local dipole moment significantly influences terminal group packing modes in the film state. This, in turn, enhances the relative dielectric constant, prolongs exciton lifetime, and reduces sub-bandgap defect states. Consequently, PBDB-TFAA-2-based OSCs achieve an exceptional FF of 0.830 and a power conversion efficiency (PCE) of 18.3%, with a ternary device reaching a PCE of 19.3%. This work highlights the potential of dipole modulation in material design to get ideal FF values for high-performance OSCs.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Adv Mater
Asunto de la revista:
BIOFISICA
/
QUIMICA
Año:
2024
Tipo del documento:
Article
Pais de publicación:
Alemania