Microstructure and photoluminescence properties of Nd-doped (Ba,Sr)TiO3 thin films

Ba0.8Sr0.2TiO3(BST) thin films with different Nd-doped concentrations have been frabracated on silicon substrates by modified Sol-gel process. All the samples were annealed at 700°C for 60 min.The structural and morphological properties of the films were examined by X-ray diffraction (XRD) and Atomic Force Microscopy (AFM). The XRD studies indicated that both pure and doped BST thin films show crystallized perovskite structures, the particle size is about 20 nm. The AFM images displayed that the films have high quality and finegrained polycrystalline structure. The photoluminescence spectra(PL) were carried out using the 808 nm Ar+ laser line as the excitation source at room temperature. The Nd-doped BST thin films show three NIR luminescence peaks corresponding to 4F3/2-4I9/2 transition at 880 nm; 4F3/2-4I11/2 transition at 1066 nm and 4F3/2-4I13/2 transition at 1345 nm; respectively. The influence of Nd3+ concentration on the microstructure and the luminescence properties were discussed. All the results showed that the Nd-doped BST films have great potential uses for novel integrated optic devices.