High-performance polythiophene thin-film transistors with nematic liquid crystal modification

The influence of nematic liquid crystal molecules on the electrical properties and microstructure of polymer semiconductors poly(3-hexylthiophene) (P3HT) was investigated. It was found that the introduction of nematic liquid crystal molecules can significantly improve the performance of P3HT thin-film transistors, providing better electrical characteristics and enhanced mobility. The field-effect mobility of the device with liquid crystal modification can be enhanced by up to a factor of ten with respect to that of the pure P3HT device. UV–visible absorption spectroscopy, X-ray diffraction, and atomic force microscopy measurements show that the enhancement of charge-carrier mobility is achieved through a more highly organized morphology and a reduction in the density of traps presents in the P3HT/liquid crystal structure. The results shown here therefore illustrate a high-performance solution-processable thin-film transistors, which is quite feasible and can pave a key step for the practical applications of organic electronic devices.

Figure optionsDownload as PowerPoint slideHighlights
► Nematic liquid crystal molecules affect poly(3-hexylthiophene) semiconductors.
► P3HT film on a liquid crystal substrate has better charge-carrier transport.
► Maximum mobility 5.45 × 10−2 cm2/V s for optimum liquid crystal thickness 25 nm.