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

Ba0.65Sr0.35TiO3 (BST) thin films doped with Ho3+ were prepared on silicon substrates by a modified sol–gel technique. The microstructure of the BST films was characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectroscopy. The results showed that 3 mol% Ho-doped BST has the largest grain size and surface root-mean square roughness. The thickness of the film was about 1.36 μm. The Ho3+ luminescence intensity reached a maximum value in the sample with 3 mol% Ho3+ ions concentration sintered at 700 °C. All the results showed that the BST: Ho3+ films may have potential use for photonic devices.