Abstract
Recently, vast amomnt of research works have been focused on improving the chemical structures and fabrication technologies for organic thin-film transistors (OTFTs) via vacuum-deposited or solution-processed organic semiconducting films. Poly(3-hexylthiophene) (P3HT) has been thoroughly studied for polymer OTFTs, but there are still some important issues remain to be solved such as the complicated synthetic process for highly ordered regioselective P3HT and high-cost material. Here we found that some substituted polyaniline can be self-assembled into layered structure similar to that of P3HT, and the synthetic process is much easier and cheaper. The butylthio-substituted polyaniline (Pan-SBu), synthesized by concurrent reduction and substitution (CRS) reaction method, was found to be able to form layered structures under appropriate casting conditions. The degree of arrangement order of Pan-SBu deposited on glass substrate highly depends on the degree of polymer chain extension in solution. The resultant lamellar structures in the cast thin film were studied by SEM, TEM, and PXRD. The charge carrier mobility of the lamellar Pan-SBu was measured based on a diode device to be 9.5 × 10-6 cm2/Vs ~ 9.5 × 10-5 cm2/Vs, which is similar to the previously reported carrier mobility (1.33 × 10-5 cm2/Vs ~ 3.30 × 10-4 cm2/Vs) of P3HT.