The Photocurrent Behavior of Perovskite Oxide Thin Films and Their Layered Structures

• Main Authors: Chia-Yu Fang, 方家宇
• Other Authors: 謝宗霖
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/74548509122306347553

碩士 === 國立臺灣大學 === 材料科學與工程學研究所 === 100 === In this study, we discuss the application of heterogeneous photocatalyst in photoelectrochemical cell. Two kinds of perovskite oxide thin films, SrTiO3 and AgNbO3, and their solid solution, (SrTiO3)x(AgNbO3)1-x were chosen as sample photoelectrode materials to study the effect of “heterojunction” on their photocurrent responses. It is found that the photocurrent responses of SrTiO3/AgNbO3 layered structures were higher than both the SrTiO3 and AgNbO3 thin films due to the help of “build-in electrical field” which could accelerate the separation of photoinduced e--h+ pairs and reduce the recombination effect. Furthermore, (SrTiO3)0.5(AgNbO3)0.5 thin film was used as a intermediate matching layer to improve the interface quality of SrTiO3/AgNbO3 layered structure. The photocurrent response was further improved by such approach. Sol-gel process was used to fabricate SrTiO3, AgNbO3 and (SrTiO3)x(AgNbO3)1-x thin films on ITO-coated glass or platinum-coated silicon wafer substrates. ITO-coated glass was chosen because of its high transparency, which can offer a wide range of applications. The shortcoming of ITO-coated glass is that it cannot endure temperature processing above 500 °C. In the study, (Pb0.86La0.14)TiO3 seeding layer and PVP modified sol-gel process were used to fabricate SrTiO3 and AgNbO3 thins films and their layered structures on ITO-coated glass substrates at 500 °C. Furthermore, the method of preparing (SrTiO3)x(AgNbO3)1-x thin films by sol-gel process is reported for the first time.