Characterization of optical transitions of Eu~（3＋） 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 5D0→7F2 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 7F1→5D1, 7F1→5D2 and 7F0→5D2 observed at 535, 472 and 465 nm in absorption spectra were 0.30×10-6, 1.36×10-6 and 0.63×10-6, respectively. The value of transi- tion probability (A), stimulated emission cross-section ( ) and radiative lifetime (τrad) corresponding to 621 nm emission peak (transition 5D0→7F2) were 308 s-1, 1.22×10-21 cm2 and 3.24×10-3 s, respectively.

Characterization of optical transitions of Eu~(3+) in lanthanum oxychloride nanophosphor