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.

A tunneling-enabled hopping mechanism is proposed, providing a pratical tool to quantitatively assess charge mobility in organic semiconductors. The paradoxical phenomena in TIPS-pentacene is well explained in that the optical probe indicates localized charges while transport measurements show bands of charge.

With the increase of alkyl chain length, the change trend of charge mobility is reversed between π–π and herringbone systems.

On the basis of three new building blocks, dithieno[3,2- b:2',3'- d]selenophene ( tt-DTS), diseleno[3,2- b:2',3'- d]thiophene ( tt-DST), and diseleno[3,2- b:2',3'- d]selenophene ( tt-DSS), four thiophene- and selenophene-based heteroacenes (3a-d) with up to seven fused rings were designed and synthesized. Another two selenophene-based heteroacenes (1 and 2) with three and five fused rings were prepared. The molecular structures of 1, 2, 3a, and 3c were confirmed by single-crystal analysis. The results showed that molecular structures, spectroscopy features, and cyclic voltammetry behaviors could be modulated by changing the heteroatoms from sulfur to selenium for 3a-d or changing the numbers of selenophene rings for 1, 2, and 3d.

New building blocks, 2,5-di(trimethylsilanyl)diseleno[2,3-b:3',2'-d]selenophene ((TMS)-DSS) and 2,5-di(trimethylsilanyl)diseleno[2,3-b:3',2'-d]thiophene ((TMS)-DST), for helicenes were obtained from selenophene with total yields of 54 and 61%. From (TMS)-DSS and (TMS)-DST, selenophene-based hetero[7]helicenes, 5,5'-di(trimethylsilanyl)benzo[1,2-b:3,4-b']bis(diseleno[2,3-b:3',2'-d]thiophene) (rac-1), and 5,5'-di(trimethylsilanyl)benzo[1,2-b:3,4-b']bis(diseleno[2,3-b:3',2'-d]selenophene) (rac-2) were prepared. The overall yields from selenophene were approximately 6.5 and 6.1%, respectively. Intermolecular interactions such as C-Se, C-S, and Se-Se were observed in the crystal packings of rac-1 and rac-2. In addition, the absorption behaviors of rac-1 and rac-2 were investigated.