Boron-doped peroxo-zirconium oxide dielectric for high-performance, low-temperature, solution-processed indium oxide thin-film transistor

We developed a solution-processed indium oxide (In₂O ₃) thin-film transistor (TFT) with a boron-doped peroxo-zirconium (ZrO₂:B) dielectric on silicon as well as polyimide substrate at 200 C, using water as the solvent for the In₂O₃ precursor. The formation of In₂O₃ and ZrO₂:B films were intensively studied by thermogravimetric differential thermal analysis (TG-DTA), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FT IR), high-resolution X-ray diffraction (HR-XRD), and X-ray photoelectron spectroscopy (XPS). Boron was selected as a dopant to make a denser ZrO ₂ film. The ZrO₂:B film effectively blocked the leakage current at 200 C with high breakdown strength. To evaluate the ZrO₂:B film as a gate dielectric, we fabricated In₂O₃ TFTs on the ZrO₂:B dielectrics with silicon substrates and annealed the resulting samples at 200 and 250 C. The resulting mobilities were 1.25 and 39.3 cm²/(V s), respectively. Finally, we realized a flexible In ₂O₃ TFT with the ZrO₂:B dielectric on a polyimide substrate at 200 C, and it successfully operated a switching device with a mobility of 4.01 cm²/(V s). Our results suggest that aqueous solution-processed In₂O₃ TFTs on ZrO₂:B dielectrics could potentially be used for low-cost, low-temperature, and high-performance flexible devices.