High-performance transparent and flexible inorganic thin film transistors: a facile integration of graphenenanosheets and amorphous InGaZnO

Abstract

Transparent and flexible thin film transistors (TFTs) with high performance based on solution processed graphene nanosheets (GNSs)–amorphous indium–gallium–zinc-oxide (a-IGZO) composites have been developed. A high electron mobility of 23.8 cm² V⁻¹ s⁻¹ has been achieved, which is about thirty times higher than those of the pristine a-IGZO TFTs (0.82 cm² V⁻¹ s⁻¹) and hydrogenated amorphous silicon (<1 cm² V⁻¹ s⁻¹). The on/off current ratio remains in a high order of 10⁶ demonstrating the sustainability of the TFT devices. In addition, transparent GNSs–a-IGZO TFTs with a Ta₂O₅ dielectric layer show superior resistance to mechanical bending with the variation of only 8% in mobility after 100 times of repeated cyclic bending compared with the degradation of more than 70% for the pristine a-IGZO device. Our results demonstrate that GNSs not only play an important role in forming a conducting network in the active matrix, but also enhance the mechanical bending stability of GNSs–a-IGZO composites. It therefore paves a key step to develop large-scale applications for next-generation transparent and flexible electronics.