Optical band gap energy of Er-doped TiO2 thin films

D.Y. Lee, J.H. Park, Y.H. Kim, I.G. Lee
Daelim University, KR

Keywords: Erbium, tatinia, spin coating, optical band gap energy


Er-doped TiO2 thin films(0~1.0 mol% Er) having a thickness of 400 to 1200 nm were spin coated onto FTO glass substrate by varying PVP concentration. The optical properties of thin films was examined by glancing angle X-ray diffraction(GAXRD) and UV-vis spectrophotometer. GAXRD results revealed that the films consisted of anatase phase and FTO. The peak intensity of (101) and (200) anatase phase decreased with increasing the Er content. The lowest band gap energy of 2.81 eV was found for the 0.7mo% Er-TiO2 thin film having a thickness of 550 nm. Er ions may be attributed to shallow trapping sites in the band structure of TiO2.