SrAl2O4: Eu2+, Dy3+ persistent luminescent materials functionalized with the Eu3+(TTA)-complex by microwave-assisted method

Abstract

Recently, several classes of rare-earth-doped luminescent materials have been drawing attention due to structurally engineered energy converting systems, capable of tuning absorption and emission spectral ranges, outlining new materials and applications in photonics. In this scenario, this work presents the development of SrAl2O4:Eu2+,Dy3+ phosphors prepared by the Pechini method, which were further APTMS-functionalized (3-aminopropyltrimethoxysilane) by microwave-assisted synthesis, incorporating a Eu3+ β-diketonate complex embedded within a SiO2-R network to increase light absorption and promote energy transfer processes. Powder X-ray diffraction data revealed a stable characteristic monoclinic phase of the SrAl2O4 host matrix, which undergoes structural changes after functionalization. Particle morphology and elemental distribution were probed by scanning electron microscopy technique, exhibiting surface alteration effects. Photoluminescence spectra displayed a characteristic broad green emission band assigned to the 4f65d1(2D) → 4f7(8S7/2) interconfigurational transition of the Eu2+ ion. Functionalized materials presented absorption shifts coupled with an emission band intensification suggesting effective interactions between the β-diketonate complex, the SiO2-R network, and the inorganic host matrix. Increased absorption range and persistence decay time under near band gap excitation on modified materials were also observed.