Tailor-Made Highly Luminescent and Ambipolar Transporting Organic Mixed Stacked Charge-Transfer Crystals: An Isometric Donor–Acceptor Approach

We have rationally designed a densely
packed 1:1 donor–acceptor
(D–A) cocrystal system comprising
two isometric distyrylbenzene- and dicyanodistyrylbenzene-based molecules,
forming regular one-dimensional mixed stacks. The crystal exhibits
strongly red-shifted, bright photoluminescence originating from an
intermolecular charge-transfer state. The peculiar electronic situation
gives rise to high and ambipolar p-/n-type field-effect mobility up
to 6.7 × 10–3 and 6.7 × 10–2 cm2 V–1 s–1, respectively,
as observed in single-crystalline OFETs prepared via solvent vapor
annealing process. The unique combination of favorable electric and
optical properties arising from an appropriate design concept of isometric D–A cocrystal has been demonstrated as
a promising candidate for next generation (opto-)­electronic materials.