Molecular Engineering of Coordination Ligand for Multifunctional Sol-Gel Oxides

Here a ligand exchange strategy for synthesizing sol-gel oxides is demonstrated to achieve multifunctionality including direct photolithography, high dielectric strength, and high charge carrier mobility, which is challenging to obtain in such oxides. For this purpose, a series of bidentate ligands with azide termini and ethylene-glycol bridges is synthesized, and these ligands are universally applicable to the synthesis of a variety of dielectric and semiconductor oxides. Optimized photolithography conditions yield a high-quality ZrO₂ dielectric film with a high dielectric constant and strength of ≈18 and ≈7 MV cm^-1, respectively. Additionally, this strategy is applied to semiconductor oxides such as In₂O₃ and ZnO, and the all-oxide-patterned solution-processed thin-film transistor (TFT) demonstrates a high charge carrier mobility of ≈40 cm² V^-1 s^-1. An oxide TFT array is fully photopatterned on a 4-inch Si wafer; uniform performances are observed across these devices. This study suggests the possibility of realizing multifunctional oxides for application in advanced electronics using simple ligand exchange chemistry.