Photothermally Activated Nanocrystalline Oxynitride with Superior Performance in Flexible Field-Effect Transistors

Photochemical reactions in inorganic films, which can be promoted by the addition of thermal energy, enable significant changes in the properties of films. Metaphase films depend significantly on introducing external energy, even at low temperatures. We performed thermal-induced, deep ultraviolet-based, thermal-photochemical activation of metaphase ZnO_xN_y films at low temperature, and we observed peculiar variations in the nanostructures with phase transformation and densification. The separated Zn₃N₂ and ZnO nanocrystalline lattice in amorphous ZnO_xN_y was stabilized remarkably by the reduction of oxygen defects and by the interfacial atomic rearrangement without breaking the N-bonding. On the basis of these approaches, we successfully demonstrated highly flexible, nanocrystalline-ZnO_xN_y thin-film transistors on polyethylene naphthalate films, and the saturation mobility showed more than 60 cm² V^-1 s^-1.