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BaSi2 O2 N2: Eu2+ phosphor was successfully synthesized by using a simple solid-state reaction method. Its properties were systematically investigated utilizing XRD, photoluminescence, excited state decay curve, afterglow emission spectra, and thermoluminescence ( TL) glow curve. With increasing temperature, its emission intensity decreases with the broadening full widths at half maximum. Particularly, its temperature-dependent afterglow emission spectra were investigated for the first time. Based on the information from TL glow curve, temperature-dependent afterglow decay curves, and afterglow emission spectra, a model was constructed to explain the mechanism of afterglow. This study provides a new perspective to use the temperature-dependent luminescence properties for studying the afterglow processes of long-lasting phosphorescence phosphors. [ABSTRACT FROM AUTHOR]

Oxynitride long-lasting phosphorescence ( LLP) phosphor SrSi2 O2 N2: Eu2+ was prepared by a new method using SrSi alloy as a precursor. Its properties were systematically investigated utilizing XRD, photoluminescence, excited-state decay curve, long-lasting phosphorescence, and thermoluminescence spectrum. This phosphor was found to be well-crystallized by calcinations of the Sr1− x Eu x Si alloy and the SiO2 mixture at 1400°C for 3 h. After irradiation under the 280 nm UV light, the afterglow emission of Eu2+ (4 f65 d1 → 4 f7) was obviously observed for at least 2 h in the limit of light perception of dark-adapted human eyes (0.32 mcd/m2). Furthermore, the possible mechanism for the LLP of SrSi2 O2 N2: Eu2+ phosphor is also discussed in this article. [ABSTRACT FROM AUTHOR]

The nitrides Ca2 Si5 N8:0.5% Eu2+, x% Tm3+( x = 0, 0.5, 1, 2, 4) ( CSN:0.5E, xT) phosphors were prepared via the high temperature solid-sintering method using CaH2 as calcium source. These phosphors exhibited strong orange long-lasting phosphorescence ( LLP) after turning off the activating light. Besides, the CSN:0.5E, 1T phosphor with an afterglow time of more than 200 min (0.32 mcd/m2). Furthermore, the temperature-dependent emission spectra of CSN:0.5E, 1T were investigated from temperature 80-500 K and an anti-quenching phenomenon that the emission intensities increased then decreased under excitation at increased temperature was found. Ultimate, the proposed mechanism on temperature dependence of luminescence was analyzed. This study provides a new perspective for the impact of temperature-dependent problem as a consequence of heating processes in luminescent materials. [ABSTRACT FROM AUTHOR]

Two types of reddish-orange afterglow emitting nitride phosphors Ca 2 Si 5 N 8 :Eu 2+ , Tm 3+ (CSN:E, T) and Ca 2 Si 5 N 8 :Eu 2+ , Tm 3+ , Dy 3+ (CSN:E, T, D) were synthesized via a solid-state reaction route and were comparatively investigated. Comparing with the di-doped CSN:E, T phosphor, the tri-doped CSN:E, T, D samples show higher afterglow intensity and longer duration time which can be attributed to the balanced defect micro-environment caused by the presence of Dy 3+ . [ABSTRACT FROM AUTHOR]

BaSi2 O2 N2: Eu2+ phosphor was successfully synthesized by using a simple solid-state reaction method. Its properties were systematically investigated utilizing XRD, photoluminescence, excited state decay curve, afterglow emission spectra, and thermoluminescence ( TL) glow curve. With increasing temperature, its emission intensity decreases with the broadening full widths at half maximum. Particularly, its temperature-dependent afterglow emission spectra were investigated for the first time. Based on the information from TL glow curve, temperature-dependent afterglow decay curves, and afterglow emission spectra, a model was constructed to explain the mechanism of afterglow. This study provides a new perspective to use the temperature-dependent luminescence properties for studying the afterglow processes of long-lasting phosphorescence phosphors. [ABSTRACT FROM AUTHOR]