Pentacene derivative/DTTCNQ cocrystals: Alkyl-confined mixed heterojunctions with molecular alignment and transport property tuning

Organic cocrystals are formed via the self-assembly of donor and acceptor constituents which are mixed together through weak noncovalent interactions. Although they revealed unique physical features, their synthesis still faced a major drawback toward the introducing of more potential semiconductors. Herein, we firstly reported soluble pentacene derivative (TMTES P) based complexes, with suitable alkyl terminal groups enabling the location of 4,8-bis(dicyanomethylene)-4,8-dihydrobenzo[1,2-b:4,5-b’] dithiophene (DTTCNQ) into the crystal lattice, thereby allowing the cocrystallization of binary system on demand. To our surprise, via varying the growth condition, the molecular disorders could be disapeared due to existed short-contacts as the locking force, and even the carrier charge changed. This organic donor-acceptor system presents unconventional insights: charge polarity control over the (opto)electronic devices and supramolecular driving force as the directional alignment guide.