Optical transition, electron-phonon coupling and fluorescent quenching of La2(MoO4)3:Eu3+ phosphor

La-2(oO(4))(3) phosphors with various Eu3+ concentrations were prepared via a facile co-precipitation process. The crystal structure and morphology of the phosphors were characterized by means of XRD and field emission scanning electron microscope. The crystal unit cell parameters a, b, and c for the monoclinic phase La-2(MoO4)(3) were calculated to be 16.989, 11.927, and 16.086 angstrom, respectively. The average size of the phosphor particles was estimated to be around 88.5 nm. The Huang-Rhys factor was derived from the phonon sideband spectra to be 0.073. The self-generated quenching process of Eu3+ was explained based on Auzel's model, and the intrinsic radiative transition lifetime for D-5(0) level was confirmed to be 0.99 ms. A new approach for calculating the Judd-Ofelt parameters was developed, meanwhile the Judd-Ofelt parameters Omega(lambda) (lambda = 2, 4, 6) of Eu3+ in La-2(MoO4)(3) phosphors were confirmed to be 10.70 x 10(-20), 1.07 x 10(-20), and 0.56 x 10(-20) cm(2), respectively. Finally, the optimal doping concentration for achieving maximum emission intensity was confirmed to be 17 mol. % by analyzing the concentration quenching. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3551584]