Influence of Au nanoparticles on the photoluminescent and electrical properties of Bi3.6Eu0.4Ti3O12 ferroelectric thin films

摘要

Au-doped Bi3.6Eu0.4Ti3O12 (BET) thin films were prepared on fused silica and Pt/Ti/SiO2/Si substrates by a chemical solution deposition method. The existence of Au nanoparticles (NPs) has been confirmed by X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscope analysis. Enhanced photoluminescence (PL) of Eu3+ ions was obtained in a wide range of Au doping level. Role of the Au NPs in the PL enhancement was investigated by means of optical absorption, excitation, and emission spectra, as well as decay lifetime measurements. The results indicated that the intra-4f transition of Eu3+ ions can be intensively activated by the coupling of the charge transfer band of BET with the 5D0 state of Eu3+ ions. The influence of Au NPs on the PL properties of Eu3+ ions in the present thin films was attributed to the band bending at Au/BET interface and the localized surface plasma resonance absorption of Au NPs in the visible light region. The dielectric and ferroelectric properties of Au-doped BET thin films were investigated as well.