Analysis the performance of TiO2 membrane deposited on different conductive material applied to pH sensors

• Main Authors: Chih Yuan Tsou, 鄒智元
• Other Authors: Jyh-Ling Lin
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/57827323732052432738

碩士 === 華梵大學 === 電子工程學系碩士班 === 95 === The objective of this work is study and analysis of TiO2 deposited on different conductive substrate including Pt, C, ITO, Cu and Al as separated extended-gate field-effect transistor (SEGFET) pH sensors. TiO2 is a metal oxide and is applied in many fields. In this thesis, TiO2 thin film was prepared using sol-gel technology. The advantages of this method are the film could be deposited on the large-area substrates, low processing temperature, very low cost of the production facilities. In this thesis, TiO2 deposited on different conductive substrates were made and analyzed in order to find the easier fabrication process and low cost. Besides, we study the characteristics such as hysteresis and drift of TiO2/Pt, TiO2/ITO and ITO sensor films which were treated at different temperature. Experimental results show good pH sensitivities when the conductive material adopted platinum, carbon, and indium tin oxide. The corresponding sensitivities are 45.78, 46.29 and 52.85 mV/pH, respectively using instrumental amplifier as readout circuit. There is no pH recognition when the conductive materials are used such as cuprum, silver, and aluminum. In different temperature (100°C, 200°C and 300°C) treatment, the results show no obvious improvement of the drift phenomenon at high heating treatment. But they can be improved in hysteresis. Otherwise, we can find the hysteresis characteristic of TiO2/ITO is better than ITO. So depositing TiO2 on ITO glass used as a pH sensor is better than ITO, especially in hysteresis measurement.