On the enhancement of luminescence efficiency of Y2O3:Eu3+ red phosphor by incorporating (Al3+, B3+) in the host lattice

To understand the mechanism of enhancement of 5D0 → 7F2 red luminescence efficiency of Eu3+ in Y2O3:Eu3+ phosphor by the presence of trace Al3+, B3+ ions in Y2O3 lattice, the effect on the crystal field strength of the host as well as the site symmetry of the activator have been investigated. A change in the characteristics of 5D0 → 7F2 decay and a sharp decrease in the build-up time of the 5D0 excited state of Eu3+ in the case of the (Al3+, B3+) containing sample vis-à-vis those of Eu3+ in the pure sample, indicated a change in the polarity of the host by Al3+ and B3+. A calculation of the Judd-Ofelt parameters of the 5D0 → 7F2 transition of Eu3+ yielded similar results.