Structural and photoluminescent analysis in Judd-Ofelt framework of color tunable SrGd2(1-x)Eu2xAl2O7 nanophosphor for white light emitting materials

Eu3+ doped SrGd2Al2O7 nanophosphor was synthesized for the first time via very economic urea assisted solution combustion approach. X-ray diffraction studies reveal that single phased SrGd2(1-x)Eu2xAl2O7 nanophosphor is developed with a heat treatment of 3 h at 1300 degrees C crystallize in tetragonal lattice with I4/mmm(139) space group. TEM (transmission electron microscopy) analysis confirms the nano scaling of the phosphor with semi spherical shaped crystallites in 40-65 nm range. Photoluminescent spectral analysis infers that these nanophosphors can be excited by NUV light yielding emission with color tunability. These nanophosphor exhibits maximum luminescent properties at 10 mol% optimal concentration. The refractive index of the host was calculated to be 2.1532. Schematic energy transfer mechanism and Judd-Ofelt intensity parameters of the nanophosphors are also examined. Concentration dependent luminescent behaviour can be indexed to tune chromaticity from blue to red region reflecting the possibility of practical application of this nano-crystalline phosphor for single phased white LEDs excited with NUV light.