Influence of Annealing Temperature on Structural Compositions and pH Sensing Properties of Sol-Gel Derived YTixOy Electroceramic Sensing Membranes

The present study was designed to determine the effect of annealing temperature on the sol-gel synthesized YTixOy electroceramic sensing membrane on silicon substrate as an electrolyte-insulator-semiconductor (EIS) based pH sensor. We observed that the YTixOy sensing membranes after annealing at high temperatures (700, 800 and 900°C) modify the structural feature, sensing characteristic and reliability. X-ray diffraction, atomic force microscopy and X-ray photoelectron spectroscopy have been used to reveal the film microstructure, surface morphology and chemical composition, respectively. As compared to the other annealed samples, the YTixOy sensing membrane annealed at 800°C manifested the highest sensitivity (58.52 mV per unit of pH), lowest hysteresis voltage (2.6 mV), and lowest drift rate (0.10 mV/h). These results demonstrate that the film annealed at 800°C suppresses the formation of oxygen vacancy and intrinsic defect forming a stoichiometric YTixOy sensing film.