High-Mobility Organic Thin Film Transistors Based on Benzothiadiazole-Sandwiched Dihexylquaterthiophenes

We report here the synthesis, characterization, and organic thin-film transistor (OTFT) mobilities of 4,7-bis(5-(5-hexylthiophen-2-yl)thiophen-2-yl)benzo[1,2,5]thiadiazole ( DH-BTZ-4T ). DH-BTZ-4T was prepared in one high-yield step from commercially available materials using Suzuki chemistry and purified by column chromatography. OTFTs with hole mobilities of 0.17 cm 2 /(Vs) and on/off current ratios of 1 × 10 5 were prepared from DH-BTZ-4T active layers deposited by vacuum deposition. As DH-BTZ-4T is soluble in common solvents, solution processed devices were also prepared by spin coating yielding preliminary mobilities of 6.0 × 10 −3 cm 2 /(Vs). The promising mobilities and low band gap (1.90 eV) coupled with solution processability and ambient stability makes this material an excellent candidate for application in organic electronics.