Thin bismuth oxide films prepared through the sol–gel method

In this paper, thin and uniform bismuth oxide films were prepared by the sol–gel method. These films were annealed at different temperatures. X-ray diffraction, X-ray photoelectron spectroscopy, atom force microscopy techniques, a surface profiler and a spectrophotometer were applied to characterize these bismuth oxide films annealed at different temperatures. The results show that different annealing temperatures cause the transformation between monoclinic phase and tetragonal phase of bismuth oxides, and that bismuth oxide films annealed at 550 °C contain the highest intensity of tetragonal phase of bismuth oxides.