Nontoxic, Eco-friendly Fully Water-Induced Ternary Zr-Gd-O Dielectric for High-Performance Transistors and Unipolar Inverters

In this context, a simple, nontoxic, and eco-friendly fully water-induced (WI) route to fabricate ternary ZrGdOx thin films at various annealing temperatures is reported. Annealing temperature dependent microstructure, morphology, optical, electrical properties, and chemical bonding states of the WI ZrGdOx thin films are investigated by x-ray diffraction, atomic force microscopy, optical spectroscopy, x-ray photoelectron spectroscopy, and electrical measurements. A low leakage current density of 10(-8) A cm(-2) at 1 mV cm(-1) and a large areal capacitance of 531 nF cm(-2) at 20 Hz are observed for 400 degrees C-annealed ZrGdOx thin films. To verify the possible applications of ZrGdOx thin films as the gate dielectric in thin-film transistors (TFTs), WI In2O3/ZrGdOx TFTs are integrated. 250 degrees C-derived full oxide In2O3/ZrGdOx TFTs have demonstrated high electrical performance and low operating voltage, including high mu(FE) of 18.82 cm(2) V-1 S-1, threshold voltage shift of 0.46 V under positive bias stress for 3600 s, and a large I-on/I-off of 6.01 x 10(7), respectively. Finally, a low voltage resistor-loaded unipolar inverter is built using In2O3/ZrGdOx TFT, exhibiting a linear relationship between supplied voltage and gain voltage and a maximum gain of 7.4 at 2.5 V. These optimized parameters have achieved a low operating voltage of 2 V, which represents a great step toward the achievement of low-cost, low-power consumption, and large-area all-oxide flexible electronics.