Structural and photoluminescence studies of red emitting CaTiO_3∶Eu~(3+) perovskite nanophosphors for lighting applications

摘要

Herein, the authors present the spectral studies with quantum efficiency of red emitting Eu~(3+) doped CaTiO_3 downconverting phosphor synthesized by chemical co-precipitation method for the demonstration on the development of solid state lighting devices. The photoluminescence properties of Eu~(3+) doped CaTiO_3 phosphors were investigated through changing the concentration of activator (Eu~(3+)). The structural, morphological and optical properties are systematically characterized by the XRD, FTIR, FESEM, PL and UV-Vis spectroscopy. The synthesized phosphor revealed the single phase orthorhombic structure with space group Pbnm. The FESEM studies exhibited the irregular morphology of the obtained phosphor particles having grain size in the range 70-170 nm. Photoluminescence spectra of CaTiO_3∶Eu~(3+) nanophosphor revealed an intense red emission peak around wavelength 619 nm in the visible region upon the excitation of near-UV light at wavelength 397 nm due to ~5D_0→~7F_2 transition in Eu~(3+). The Judd-Ofelt intensity parameters were calculated and the quantum efficiency of optimized composition (for Ca_(0.95)TiO_3∶0.05Eu~(3+)) is found to be 17.46 %. The photometric characterization results revealed that the prepared phosphor can be a suitable candidate for application of solid state lighting devices.