Self-assembly and charge transport properties of a benzobisthiazole end-capped with dihexyl thienothiophene units

Abstract

The synthesis of a new conjugated material is reported; BDHTT-BBT features a central electron-deficient benzobisthiazole capped with two 3,6-dihexyl-thieno[3,2-b]thiophenes. Cyclic voltammetry was used to determine the HOMO (-5.7 eV) and LUMO (-2.9 eV) levels. The solid-state properties of the compound were investigated by X-ray diffraction on single-crystal and thin-film samples. OFETs were constructed with vacuum deposited films of BDHTT-BBT. The films displayed phase transitions over a range of temperatures and the morphology of the films affected the charge transport properties of the films. The maximum hole mobility observed from bottom-contact, top-gate devices was 3 × 10-3 cm2 V-1 s-1, with an on/off ratio of 104-105 and a threshold voltage of -42 V. The morphological and self-assembly characteristics versus electronic properties are discussed for future improvement of OFET devices. © The Royal Society of Chemistry.