Structural, luminescent and thermal properties of blue SrAl2O4:Eu2+, Dy3+ phosphor filled low-density polyethylene composites

The performance of nanophase luminophors is usually compromised by environmentally induced degradation. In this study, composites of low density polyethylene (LDPE) with various concentrations of the blue-emitting europium and dysprosium co-doped strontium aluminate (SrAl2O4:Eu2+,Dy3+) phosphor were investigated. The blue long-lasting phosphorescence of the composites was observed in the dark after removal of the excitation light. X-ray diffraction analysis revealed the presence of the SrAl2O4 phase in the composites. PL spectra of the composites have two sets of peaks, major broad bands peaking at about 4855 Å and minor ones at wavelengths between 4115 and 4175 Å, attributed to the 4f–5d transition of Eu2+. DSC and TGA results show that the introduction of the phosphor in LDPE matrix caused a slight reduction in the crystallinity of LDPE but a significant increase in the stability of the composites.