Inkjet printing of amorphous indium aluminum oxide active layers for high-performance thin-film transistors

Oxide semiconductors are regarded as a kind of promising active materials for thin-film transistors (TFTs) to drive organic light-emitting diodes (OLEDs) because of their advantages of high mobility, good electrical uniformity, and low cost. In this study, excellent metal oxide TFTs were successfully fabricated with a inkjet printer without any photolithography step. Indium aluminum oxide (IAO) active layers were fabricated at relative low post-annealing temperature and shown a n-type semiconductor behavior. The precursor solution with coalescing aid provided high-quality films, resulting in optimal device performance characteristics including a highest mobility of 59.7 cm²/V·s, steep subthreshold swing of 0.224 V/dec and high on/off ratio exceeding 9 × 10⁶. These advantageous characteristics of the printed TFTs are very promising for future OLEDs, medical electronics, and large-scale integration of printed electronics.