Color emission and dielectric properties of Eu-doped Gd₂O ₃ gate oxide thin films

High-k Gd₂O₃ used for thin film transistor (TFT) gate insulators has been synthesized via a simple solution process. Phase analysis and capacitive performance reveal that a high dielectric constant of ∼ 20 and a low leakage current level of < 10^-8 A/cm² at 1 MV/cm with a good transparency under the visible wavelength region are readily produced by the sol-gel method. Eu³⁺ doping leads to an increased dielectric constant induced by the additional electric dipole transition, which is evidently visualized by the photoluminescence behavior and/or by the defect-controlled thin film microstructures. Thus, the solution-processed (Gd,Eu)₂O₃ film is a viable gate insulator to be considered for the proposed "color emissive" switching devices as well as for the low power-driven TFT devices.