Single-Band Ratiometric Thermometry Strategy Based on the Completely Reversed Thermal Excitation of O → Eu CTB Edge and Eu 4f → 4f Transition.

Single-band ratiometric (SBR) strategies present huge potential in the field of luminescence intensity ratio thermometry owing to their excellent signal discrepancy and appealing simplicity. Herein, we employ the approach of Na replacing Li in the LiYGeO:Eu phosphor to regulate the thermal stability of the O → Eu charge-transfer band (CTB) and obtain significant thermal enhancement of luminescence under CTB edge excitation. Combined with the obvious thermal quenching of luminescence under ground-state absorption excitation, the ratio of the single emission band increases by 18 times when the temperature increases from 300 to 570 K.

Sunlight-Activated Orange Persistent Luminescence from Bi-Doped SrBaZnGaO for Warm-Color Optical Applications.

A warm persistent luminescence (PersL) material SrBaZnGaO:Bi was prepared using the conventional high-temperature solid-phase reaction method. We first investigated the PersL properties of SrBaZnGaO:Bi in detail via PersL spectra, PersL excitation spectrum, PersL decay curves, and thermoluminescence (TL) spectra. The highlight of this study is that in addition to the 254 nm light source, the low-energy light source of 365 nm and sunlight can effectively excite electrons and charge traps, resulting in preferable orange PersL performance.

A two-step solid-state reaction to synthesize the yellow persistent GdAlGaO:Ce phosphor with an enhanced optical performance for AC-LEDs.

By using a two-step solid-state reaction to synthesize the yellow-persistent GdAlGaO:Ce phosphor, both the luminescence and afterglow properties were greatly enhanced. Its internal quantum efficiency reaches as high as 81.9%, indicating its promising application in reducing the flicker effect in AC-LED-based white light systems.

Excellent optical thermometry based on single-color fluorescence in spherical NaEuF₄ phosphor.

Temperature-dependent luminescence of spherical NaEuF₄ phosphors with different particle sizes was studied. The thermally coupled ⁵D₀ and ⁵D₁ level of Eu³⁺ was observed. The linear dependence of emission intensities of ⁵D₀ level of NaEuF₄ phosphor on temperature confirmed the excellent temperature sensing performance.

[Effect of PbO on emission properties of YAG:Ce3+ phosphor].

Doubly doped YAG:Ce3+, Pb2+ phosphor was obtained by doping YAG:Ce3+ phosphor with PbO. Compared with the emission spectra of YAG:Ce3+ phosphor without PbO, the Ce3+ emission band of YAG:Ce3+, Pb2+ shifts to longet wave, which can enhance the red component of spectrum. Meanwhile, the intensity of Ce3+ emission is increased by 10% when the concentration of PbO is 5%, SEM image indicates that PbO may act as a flux.

[Effect of different excitation monitoring wavelengths on emission spectrum of red long afterglow phosphor Sr3Al2O6 : Eu2+, Dy3+].

The Eu2+ and Dy3+ ion co-doped Sr3Al2O6 phosphor powders with long afterglow were prepared with high temperature solid-state reaction. The phase and the spectra properties of the material were characterized by X-ray diffraction (XRD) and fluorescence spectrophotometer. It was found that the sample is composed of pure Sr3Al2O6 phase.