Structural Polymorphism and Thin Film Transistor Behavior in the Fullerene Framework Molecule...

The molecular structure of the hydrocarbon 5,6;11,12-di-o-phenylenetetracene (DOPT), its material characterization and evaluation of electronic properties is reported for the first time. A single-crystal X-ray study reveals two different motifs of intramolecular overlap with herringbone-type arrangement displaying either face-to-edge or co-facial face-to-face packing depicting intensive π-π interactions. Density functional theory (DFT) calculations underpin that a favorable electronic transport mechanism occurs by a charge hopping process due to a π-bond overlap in the DOPT polymorph with co-facial arene orientation. The performance of polycrystalline DOPT films as active organic semiconducting layer in a state-of-the-art organic field effect transistor (OFET) device was evaluated and proves to be film thickness dependent. For 40 nm layer thickness it displays a saturation hole mobility (μhole ) of up to 0.01 cm(2)  V(-1)  s(-1) and an on/off-ratio (Ion /Ioff ) of 1.5×10(3) .