Synthesis and Transistor Application of Bis[1]benzothieno[6,7-d:6′,7′-d′]benzo[1,2-b:4,5-b′]dithiophenes

Four bis [1]benzothieno [6,7-d:6',7'-d'] [1,2-b:4,5-b'] dithiophene (BBTBDT) derivatives bearing substituents on the molecular long axis were synthesized, and their transistor performance was evaluated. Among the obtained compounds, OFET devices based on the 2,9-diphenyl-substituted derivative (Id) on a beta-PTS-modified Si/SiO2 substrate yielded the best morphological and crystalline structures, resulting in the highest hole mobility, as high as 0.16 cm(2) V-1 s(-1), and a low threshold voltage of 8 V. In the solid state, id formed a highly ordered and crystalline edge-on structure, which facilitated effective carrier transport. The detailed structure property relationships were also disclosed by GIWAXS analysis, atomic force microscopy measurements, and theoretical calculations.