Enhanced luminescence by monovalent alkali metal ions in Sr2SiO4:Eu3+ nanophosphor prepared by low temperature solution combustion method

Abstract

A series of red light emission phosphors of Sr2SiO4:Eu3+ (1–5mol%) and Sr2SiO4:Eu3+:M+ (M+=Na+, K+ and Li+) were prepared through simple low temperature solution combustion method and their luminescence properties were studied. The powder X-ray diffraction (XRD) results revealed the formation of highly crystalline Sr2SiO4:Eu3+ nanophosphor having an average particle size 45–60nm and strain was measured to be (2.4–3.1)×103. The SEM pictures of Sr2SiO4:Eu3+ and Sr2SiO4:Eu3+: M+ showed porous in nature and irregular shaped particles. The phosphors can be effectively excited by the light of 395nm and show the characteristic emission peaks assigned to transitions of 5D0→4FJ (J=0, 1, 2, 3, 4). The excitation and emission spectra indicate that the phosphors can be effectively excited by UV (∼395nm) light which emits an intense red light peaked at ∼614nm. The Eu3+ concentration quenching mechanism was verified to be multipole–multipole interaction and critical energy transfer distance (RC) was 16.43nm. The effects of different concentration of Eu3+ and charge compensations on luminescence properties were discussed. The highest PL intensity was recorded for 4mol% Eu3+ ions. Further, Li+ (0.03) has the best charge compensation effect followed by Na+ and K+ respectively. The γ-induced studies showed three glow peaks at 211, 163 and 243 (shouldered peaks) respectively at a warming rate of 5°Cs−1. The glow peak intensity at 163°C increases linearly up to 3kGy and after that it decreases. Up to 3kGy, the phosphor was quite useful for radiation dosimetry.