English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Electronic and optical properties of doped organic semiconductors aredominated by local interactions between donor and acceptor molecules. However,when such systems are in crystalline form, long-range order competes againstshort-range couplings. In a first-principles study on three experimentallyresolved bulk structures of quaterthiophene doped by (fluorinated)tetracyanoquinodimethane, we demonstrate the crucial role of long-rangeinteractions in donor/acceptor co-crystals. The band structures of theinvestigated materials exhibit direct band-gaps decreasing in size withincreasing amount of F atoms in the acceptors. The valence-band maximum andconduction-band minimum are found at the Brillouin zone boundary and thecorresponding wave-functions are segregated on donor and acceptor molecules,respectively. With the aid of a tight-binding model, we rationalize that themechanisms responsible for these behaviors, which are ubiquitous indonor/acceptor co-crystals, are driven by long-range interactions. The opticalresponse of the analyzed co-crystals is highly anisotropic. The absorptiononset is dominated by an intense resonance corresponding to a charge-transferexcitation. Long-range interactions are again responsible for this behavior,which enhances the efficiency of the co-crystals for photo-induced chargeseparation and transport. In addition to these results, our study clarifiesthat cluster models, accounting only for local interactions, cannot capture therelevant impact of long-range order in donor/acceptor co-crystals.

Long-Range Order Promotes Charge-Transfer Excitations in Donor/Acceptor Co-Crystals