Characterization of optical transitions of Eu3+ in lanthanum oxychloride nanophosphor

This paper presented the studies on the optical properties and calculation of spectral parameters of europium doped lanthanum oxychloride nanophosphor for their possible applications in optoelectronic devices. The compound was doped with 0.1 mol% Eu3+ ions. The X-ray diffraction study of prepared sample suggested the tetragonal structure with particle size in the range of 18-21 nm. The photoluminescence (PL) emission spectra showed the bright emission in orange-red region from 580 to 630 nm. The most intense emission peak at 621 nm was due to transition D-5(0)-> F-7(2) in energy levels of Eu3+ ions. The spectral parameters were calculated from the absorption and emission spectra using Judd-Ofelt intensity parameters. The calculated values of the oscillator strength corresponding to the three transitions (F1 -> D1)-F-7-D-5, F-7(1)-> D-5(2) and F-7(0)-> D-5(2) observed at 535, 472 and 465 nm in absorption spectra were 0.30x10(-6), 1.36x10(-6) and 0.63x10(-6), respectively. The value of transition probability (A), stimulated emission cross-section (sigma(E)(p)) and radiative lifetime (tau(rad)) corresponding to nm emission peak (transition (D0 -> F2)-D-5-F-7) were 308 s(-1), 1.2,2x10(-21) cm(2) and 3.24x10(-3) s, respectively.