Photoluminescence properties of Pr3+ doped Bi2ZnOB2O6 microcrystals and PMMA-based composites

Photoluminescence properties of red-emitting Pr3+-doped Bi2ZnOB2O6 microcrystalline powder and PMMA-based composite materials were reported. Bi2ZnOB2O6:Pr3+ powders were synthesized by means of the modified Pechini method. The morphology and crystallographic structure of Bi2ZnOB2O6:Pr3+ microcrystals were investigated by XRD and HRTEM. The PMMA-based composite materials were prepared by embedding of Bi2ZnOB2O6:Pr3+ powder in the PMMA matrix. The vibrational properties of the powder and composite systems were investigated by mu-Raman spectroscopy. Emission spectra of the samples were measured under blue (451.6 nm) and UV (320 nm) excitation. Both, the powder and composite samples show enhancement of red emission (D-1(2)-> H-3(4)) and quenching of greenish-blue luminescence from P-3(0) level of Pr3+ ions after excitation in UV and VIS caused by the P-3(0) similar to D-1(2) non radiative relaxation of Pr3+ ion by low-lying charge transfer state and non-radiative de-excitation through Pr3+-Bi3+ energy transfer. The response of the powder and composite samples to pulsed excitation at 451.6 nm was measured by monitoring emission from the D-1(2) level (595 nm/Po-3 -> H-3(6) transition). The determined lifetimes tau(1) and tau(2) of the red emission at 595 nm (D-1(2) -> H-3(4) transition) of the composite are significantly longer in comparison to powder samples. Moreover, because of the good nonlinear optical properties of the Bi2ZnOB2O6 crystals and effective luminescence of the Pr3+-doped Bi2ZnOB2O6 powders and composites, they can be very useful as bi-functional materials in the new generation of optoelectronic devices. (C) 2016 Elsevier B.V. All rights reserved.