Synthesis of π-extended oxacenes and their application to organic field-effect transistors

A variety of heteroacenes have been developed in the last decades as promising organic semiconducting materials for organic field effect transistors (OFETs). However, furan-fused ones have been rarely seen in literatures until very recently. Here we demonstrate the synthesis of dibenzo[ d , d ']naphtho[2,3- b :6,7- b ']difurans (DBNDFs) and their application as the active layers for OFETs. Unsubstituted and didecyl-substituted DBNDFs were successfully synthesized. Thermal and photophysical properties were examined by thermogravimetric analysis, differential scanning calorimetry, and UV/Vis absorption and photoluminescence spectroscopies as well as theoretical calculations. The out-of-plane X-ray diffraction measurement and atomic force microscopy of their thin films revealed that the DBNDF π-core are arranged with their long axes perpendicular to the substrate. The OFET devices were fabricated with DBNDFs as the active layers, exhibiting typical p-type transport characteristics. In particular, the hole mobility of the OFET devices based on the didecyl-substituted DBNDF reached as high as 0.62 cm 2 ⋅ V −1 ⋅ s −1 . • Linearly π-extended furan-fused compounds, dibenzo[ d , d ']naphtho[2,3- b :6,7- b ']difurans (DBNDFs) were synthesized. • Organic field-effect transistor devices with DBNDFs exhibited high hole mobility of up to 0.62 cm 2 ⋅V −1 ⋅s −1 . • The DBNDF π-core formed the layered structure ideal for the carrier transport between source and drain electrodes.