Comparison of CeTiO3 and Ce2TiO5 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.