Judd-Ofelt analysis of Ho3+ doped in ceramic CaSc2O4

A Judd-Ofelt analysis was performed on a calcium scandate (CaSc2O4) ceramic sample doped with 2 at% Ho3+. Using the measured lifetime of I-5(7) level to calibrate the absorption spectrum, the Judd-Ofelt parameters were obtained: Omega(2) = 3.78 x 10(-20) cm(2), Omega(4) = 5.17 x 10(-20) cm(2), and Omega(6) = 1.92 x 10(-20) cm(2). The electric-dipole and magnetic-dipole transition probabilities, radiative lifetimes and luminescence branching ratios were calculated. The quantum efficiency of the green emitting levels (F-5(4), S-5(2)) was found: 54%. The calibration method also allowed the estimation of the 'effective' thickness of the ceramic sample: approximately eight times greater than the geometric thickness. (C) 2015 Elsevier B.V. All rights reserved.