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

Ba0.65Sr0.35TiO3 (BST) thin films with different Nd-doped concentration 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). XRD studies indicated that both pure and doped BST thin films show well-crystallized perovskite structures, the particle size is about 20 nm. AFM images display the films have high quality and fine-grained 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 876 nm; 4F3/2-4I11/2 transition at 1060 nm and 4F3/2-4I13/2 transition at 1337 nm respectively. Influence of Nd3+ concentration to the microstructure and the luminescence properties were discussed. All the results showed that the Nd-doped BST films may have great potential use for novel integrated optic devices.