Combustion synthesis of Ba2Ca(BO3)2:Eu2+ phosphors and position of 4f and 5d energy levels of lanthanides in Ba2Ca(BO3)2 host lattice

In this work, Eu2+ doped Ba2Ca(BO3)2 was fabricated by combustion method at various conditions of fuel and annealing temperature. X-ray diffraction (XRD), scanning electron microscope (SEM), photoluminescence (PL) spectra were used to investigate the optimal conditions for preparation of Ba2Ca(BO3)2:Eu2+ phosphors. Eu3+ state in Ba2Ca(BO3)2 host lattice was obtained by annealing the Ba2Ca(BO3)2:Eu2+ at 700 °C in air and its phonon sideband spectrum was analyzed to find phonon energies. Charge transfer energy determined from excitation spectra of Ba2Ca(BO3)2:Eu3+ sample was used to predict energy level of lanthanide (Ln) ions. The vacuum referred binding energy (VRBE) scheme for all lanthanides in the Ba2Ca(BO3)2 host lattice has been constructed and used to discuss the possibility of several Ln3+ ions doped Ba2Ca(BO3)2 as thermoluminescence materials.