Due to their outstanding electronic properties and high optical transparency, metal oxide thin-film transistors have significant potential in state-of-the-art flat panel display technologies. Here, high performance solution-processed metal oxide thin-film transistors were realized by fabricating heterojunctions of indium oxide (In2O3) and polyethylenimine (PEI) as the semiconducting channel layer. Due to the tunable work function of the In2O3-PEI blends, electron mobilities as high as ~10 cm2V-1s-1 were obtained. These device metrics exceed those of the single In2O3 and PEI layers due to the generation of a two-dimensional electron gas (2DEG). This work represents the first demonstration of 2DEG-based heterojunction oxide thin-film transistors with broad implications for next-generation electronic applications.
