Formamide Mediated, Air-Brush Printable, Indium-Free Soluble Zn–Sn–O Semiconductors for Thin-Film Transistor Applications

In this study, for high-performance indium-free metal oxide channel layer, we synthesize Zn–Sn–O (ZTO) precursor solutions in which formamide is incorporated as an additive for catalyzing the subsequent sol–gel reactions and the evolution of chemical structure. It is revealed that the formamide plays a critical chemical role in evolving a chemical structure with more oxygen-deficient oxide lattice and with less hydroxide, allowing for high field-effect mobility over 7 cm2/V·s. Furthermore, it is for the first time demonstrated that electrically active metal-oxide films can be patterned, using an air-brush printing technique, by directly depositing formamide-mediated ZTO-precursor solutions in patterned geometries.