Phosphor Polymer Nanocomposite: SrAl2O4:Eu2+, Dy3+ Embedded PMMA for Solid-State Applications

Abstract

Abstract In this work, PMMA/ SrAl2O4:Eu2+, Dy3+ polymer nanocomposite films were synthesized by solution casting method. The crystal structure, morphological, photoluminescence properties and thermal properties were investigated using various characterization techniques. Prepared polymer nanocomposite films (PNC) were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy for its structural and morphological properties. Photoluminescence spectroscopy (PL) and UV-Vis Spectroscopy (UV-Vis) were studied to know the optical behavior of these synthesized PNC films. To know the thermal behaviour of these films, Thermo gravimetric Analysis (TGA) and Differential Thermal Analysis (DTA) were also investigated. From the XRD data of pristine phosphor SrAl2O4:Eu2+, Dy3+ and PNC films PMMA/ SrAl2O4:Eu2+, Dy3+, formation of single phase was observed with a monoclinic structure. The average crystalline size was calculated using Debye-Scherrer formula and was found in the range of 40-45 nm. From PL studies, a peak at 520 nm is observed in pure phosphor as well as PNC film, which is assigned to 4f65d1→4f7 electronic transition of Eu2+ in the SrAl2O4:Eu2+. These PNC films show high colour purity with the CIE coordinate (0.25, 0.57) lying in green region of the colour coordinate diagram. The optical band gap is also obtained which reveals that the band gap of pure phosphor is more as compared to the fluorescent nanocomposites. These results suggest that PMMA/ SrAl2O4:Eu2+, Dy3+ can be a promising candidate as a green emitting polymer nanocomposite film for application in solid state lighting.