Physicochemical and optical properties of one-pot combustion synthesized Pr doped La2O3/La(OH)3

Abstract

Different concentrations of Pr doped La2O3 and La(OH)3 nanopowders are synthesized by solution combustion method. The X-ray diffraction (XRD) analysis confirms the pure phase and hexagonal structure of compounds. The physical and optical properties are investigated and compared. X-ray photoelectron spectroscopy (XPS) confirms the presence of both Pr3+ and Pr4+ in 15 atom % Pr doped La2O3. The band gap of La2O3 and La(OH)3 decreases significantly after Pr doping. Further, photoluminescence (PL) studies of Pr doped La2O3/La(OH)3 compounds show a sharp green emission due to 3P0 ? 3H4 transition of Pr3+ ions, and the emission properties depend upon the doping concentration. The emission intensity of Pr3+ is optimized with concentration. Hydroxides show slightly lower emission intensity compared to oxides. 1 atom % Pr doped La2O3 (La1.98Pr0.02O3) heated at higher temperatures shows slightly higher emission intensity compare to heated at low temperature due to the increase in crystallites size. 1 atom % Pr doped La2O3 (oxide) shows the highest emission intensity in all the compounds (oxides/hydroxides).