Comparison of CeTiO 3 and Ce 2 TiO 5 Sensing Films for pH Sensors

In this letter, we compared the structural and sensing properties of CeTiO 3 and Ce 2 TiO 5 sensing films for electrolyte–insulator–semiconductor (EIS) pH sensors. The structural behavior of these sensing films was characterized by Auger electron spectroscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. In comparison with CeTiO 3 sensing film, the EIS sensor using a Ce 2 TiO 5 sensing film exhibited better sensing performance including higher sensitivity (68.35 mV/pH), lower hysteresis voltage (0.9 mV), and smaller drift rate (0.19 mV/h), presumably suggesting this film possessing a high fraction of Ce 3+ and a rough surface.