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 cm(2)/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.