Effect of Er doping on microstructure and optical properties of ZnO thin films prepared by sol-gel method

Er doped ZnO (EZO) thin films were successfully prepared by sol-gel spin coating method on quartz glass substrates. The effect of Er doping content on the microstructure and optical properties of EZO thin films were investigated. The X-ray diffraction and X-ray photoelectron spectroscopy results indicate that Er was successfully incorporated into the EZO thin films and substituted the Zn sites. The incorporation of Er could affect the band gap (E (g) ) and optical constants of ZnO thin films. The photoluminescence spectra show that the 1.54 mu m emission, which originates from the transition of Er3+: 4I(13/2) -> 4I(15/2), was observed in EZO thin films. Furthermore, it is demonstrated that the formation of singly ionized oxygen vacancies (V (O center dot)) could be inhibited by the incorporation of Er dopant, which is supported by further defect formation energies calculations.