Structural characterization and luminescence properties of bluish-green-emitting SrCaMgSi₂O₇:Eu²⁺, Dy³⁺ phosphor by solid-state reaction method

Abstract

An excellent long afterglow SrCaMgSi₂O₇:Eu²⁺, Dy³⁺ phosphor was prepared by the high-temperature solid-state reaction method. The phase structure of prepared phosphor was an akermanite-type structure, which belongs to the tetragonal crystallography with space group ${\text{P}}\overline{{{\text{42}}}} _{{\text{1}}} {\text{m}}$. Chemical composition of the sintered SrCaMgSi₂O₇:Eu²⁺, Dy³⁺ phosphor was confirmed by EDX. Under ultraviolet excitation, the SrCaMgSi₂O₇:Eu²⁺, Dy³⁺ phosphor would emit bluish-green (cyan) light, belonging to the broad emission band ascribed to the 4f⁶5d¹ → 4f⁷ transition. Investigation of afterglow properties show that SrCaMgSi₂O₇:Eu²⁺, Dy³⁺ phosphor held a fast and slow decay process. The peak of ML intensity increases linearly with increasing impact velocity of the moving piston. The CIE chromaticity diagram and ML spectra show a similar spectrum as PL spectra, which indicated that ML is emitted from the same emitting center of Eu²⁺ ions. Thus the present investigation indicates that the piezoelectrically induced de-trapping model is responsible to produce ML in prepared SrCaMgSi₂O₇:Eu²⁺, Dy³⁺ phosphor.