Fullerene/sulfur-bridged annulene cocrystals: two-dimensional segregated heterojunctions with ambipolar transport properties and photoresponsivity.

Fullerene/sulfur-bridged annulene cocrystals with a two-dimensional segregated alternating layer structure were prepared by a simple solution process. Single-crystal analysis revealed the existence of continuing π-π interactions in both the donor and acceptor layers, which serve as transport paths for holes and electrons separately. The ambipolar transport behaviors were demonstrated with single-crystal field-effect transistors and rationalized by quantum calculations. Meanwhile, preliminary photoresponsivity was observed with the transistor configuration.