Structural and optical investigations on LaGaO3 synthesis by sol–gel method along with a blue luminescence property

Abstract

• LaGaO 3 perovoskite material has been successfully synthesized by a simple rout called sol gel method. • The efficiency of sol–gel methods to obtain pure phase of LaGaO3 was proved. • Raman reveals 9 bands that correspond to active optical-vibrational modes of orthorhombic symmetry that is in good agreement with XRD results. • A special emphasis is put on the photoluminescence properties of this material. Temperature-dependent PL, low-temperature analysis has been carried out. This work presents the preparation of Lanthanum Gallate peroveskite (LaGaO3) by sol–gel based Pechini method at low temperatures. The structural and optical properties of the elaborated material were investigated, by means of X-ray diffraction (XRD), Raman, UV–visible and Photoluminescence (PL) Spectroscopies. The XRD pattern showed a pure orthorhombic phase of LaGaO3 annealed at 600 °C. The orthorhombic symmetry was confirmed by Raman study. The band gap energy was estimated from UV–visible diffuse reflectance spectra to be 3.64 eV. Photoluminescence spectra of LaGaO3 showed two bands in blue region. For a complete understanding of the luminescence properties, a temperature-dependent PL analysis was studied. The temperature dependence for LaGaO3 sample revealed an S-shape behavior. The S-shape phenomenon and the variation of the FWHM values as a function of temperature were discussed. Finally, the thermal activation energy was calculated from the integrated PL intensity as a function of inverse temperature in orders to determinate the thermal stability of material.