Photoelectrochemical properties of Hematite thin film photoelectrodes prepared by reactive magnetron sputtering

  • Miss Pei-Chun Chen, Energy and Environment Laboratory, Industrial Technology Research Institute, Taiwan
  • Mr Ming-Shan Jeng, Energy and Environment Laboratory, Industrial Technology Research Institute, Taiwan
  • Dr Kong-Wei Cheng, Department of Chemical and Materials Engineering, Chang Gung University, Taiwan
  • Mr Chung-jen Tseng, Department of Mechanical Engineering, NCU., Taiwan
  • Mr Chih-Hao Wang, Department of Mechanical Engineering, NCU., Taiwan
  • Wen-Sheng Chang, Energy and Environment Laboratory, Industrial Technology Research Institute, Taiwan
  • Chien-Chung Huang, Energy& Environment Research Lab, Industrial Technology Research Institute, Taiwan

    • Hematite with a band gap of 2.2eV is a potential candidate for photoelectrochemical hydrogen production utilizing solar energy. In this study, high-quality iron oxide(α-Fe2O3) films using reactive-sputtering process is reported along with their structural characterization and application to water splitting. Pure iron target and argon carrier gas were used in the process. Hematite thin films were deposited on ITO glasses under various oxygen partial pressure ratios from 9%~36% and substrate temperatures from 150oC to 450 oC. The bulk properties of α-Fe2O3 were analyzed orientation of the crystallites. The hematite thin films prepared under lower temperature (150ºC) and low oxygen partial pressure (PO2%:9%) exhibits dominant (300) peaks. On the other hand, (104) orientation is enhanced at higher temperature (450ºC) in any oxygen partial ratio. The photocurrents and stability were measured in sodium hydroxide under the illumination of Xe light. A maximum photocurrent density of 4.9 mA/cm2 was observed in samples prepared at 450ºC substrate temperature and 18% oxygen partial pressure ratio, under 0.7V /SCE bias and 100 mW/cm2 Xe light illumination.