4.8 Article

Complete Peripheral Fluorination of the Small-Molecule Acceptor in Organic Solar Cells Yields Efficiency over 19?%

Journal

Publisher

WILEY-V C H VERLAG GMBH
DOI: 10.1002/anie.202312630

Keywords

CH-Series Acceptors; Energy Conversion; Fluorides; Molecular Packing; Organic Solar Cells

Ask authors/readers for more resources

By performing complete peripheral fluorination on a two-dimensional conjugation extended molecular platform of CH-series small molecular acceptors (SMAs), an acceptor of CH8F with eight fluorine atoms surrounding the molecular backbone was obtained. This method improves the ordering of molecular packings, reduces exciton binding energies, and achieves an efficiency of 18.80% for D18:CH8F-based organic solar cells, which is better than the efficiency of 17.91% for CH6F-based ones.
Due to the intrinsically flexible molecular skeletons and loose aggregations, organic semiconductors, like small molecular acceptors (SMAs) in organic solar cells (OSCs), greatly suffer from larger structural/packing disorders and weaker intermolecular interactions comparing to their inorganic counterparts, further leading to hindered exciton diffusion/dissociation and charge carrier migration in resulting OSCs. To overcome this challenge, complete peripheral fluorination was performed on basis of a two-dimensional (2D) conjugation extended molecular platform of CH-series SMAs, rendering an acceptor of CH8F with eight fluorine atoms surrounding the molecular backbone. Benefitting from the broad 2D backbone, more importantly, strengthened fluorine-induced secondary interactions, CH8F and its D18 blends afford much enhanced and more ordered molecular packings accompanying with enlarged dielectric constants, reduced exciton binding energies and more obvious fibrillary networks comparing to CH6F controls. Consequently, D18:CH8F-based OSCs reached an excellent efficiency of 18.80 %, much better than that of 17.91 % for CH6F-based ones. More excitingly, by employing D18-Cl that possesses a highly similar structure to D18 as a third component, the highest efficiency of 19.28 % for CH-series SMAs-based OSCs has been achieved so far. Our work demonstrates the dramatical structural multiformity of CH-series SMAs, meanwhile, their high potential for constructing record-breaking OSCs through peripheral fine-tuning. Complete peripheral fluorination was performed on a two-dimensional conjugation extended molecular platform of CH-series small molecular acceptors (SMAs), rendering an acceptor of CH8F with eight fluorine atoms surrounding molecular backbone. More importantly, the highest efficiency of 19.28 % for CH-series SMAs-based organic solar cells has been achieved so far.+image

Authors

I am an author on this paper
Click your name to claim this paper and add it to your profile.

Reviews

Primary Rating

4.8
Not enough ratings

Secondary Ratings

Novelty
-
Significance
-
Scientific rigor
-
Rate this paper

Recommended

No Data Available
No Data Available