Optical characterization and Judd-Ofelt analysis of Pr3+ ions in sol-gel derived zirconia/polyethylene glycol composite

The photoluminescence characteristics of praseodymium (Pr3+) doped zirconia/polyethylene glycol (ZrO2/PEG) samples were studied using optical absorption and emission spectra. The optical properties were theoretically analysed using standard and modified Judd-Ofelt (J-O) models. The oscillator strength of the observed transitions and J-O intensity parameters were calculated using these J-O models. The radiative properties such as radiative transition probability (AT), branching ratio (βR), stimulated emission cross-section (σe) and gain band width (σe×Δλeff) for the excited states of Pr3+ in ZrO2/PEG composite have been determined. The experimental branching ratios obtained from the emission spectra were compared with the theoretical values. The excitation spectra of Pr3+ doped samples show overlapping of Pr3+ excitation peak at 448 nm at the end of the broad excitation band of the host, indicating the charge transfer between the host and Pr3+ ions. Luminescence decay analysis confirmed concentration quenching in the prepared samples and the lifetime values are found to be in the microsecond range.