Eu³⁺-Activated Alkali Rare-Earth Double-Tungstate Nanoparticles for Near-Ultraviolet-Light-Triggered Indoor Illumination

Abstract

Phosphors for near-ultraviolet (NUV)-triggered white light-emitting diodes (LEDs) have become an attractive research topic in recent years. However, it is still difficult for phosphors to have simultaneous high luminous intensity, superior color purity, and excellent thermal stability. Hence, a series of Eu3+-activated alkali rare-earth double-tungstate nanoparticles with high luminescence intensity were prepared by a facile hydrothermal reaction method. The influence of rare-earth ions and alkali cations on the luminescence properties was investigated. Impressively, the prepared phosphors exhibit superior color purity and excellent thermal stability. Meanwhile, the emission intensity and color purity can be controlled by tuning the concentrations of Eu3+ ions. By employing the resultant nanoparticles, a fabricated LED device emitted bright warm white light with a high color rendering index (CRI) of 92.12 and a suitable correlated color temperature (CCT) of 4689 K. This work straightly confirms that the prepared phosphors are promising candidates as red-emitting components applied in NUV-triggered indoor illumination.

Optimized Gd2O2S:Pr Scintillation Films for X-ray Flat Panel Imaging: Balancing Enhanced Efficiency with Flexibility

“…The analysis of the graph facilitated the determination of Δ E values . For the Gd 2 O 2 S:Pr phosphor without and with Li 2 CO 3 as a fluxing agent, the calculated Δ E values were found to be 0.297 and 0.355 eV, respectively, as shown in Figure (d).…”

“…The analysis of the graph facilitated the determination of ΔE values. 37 For the Gd 2 O 2 S:Pr phosphor without and with Li 2 CO 3 as a fluxing agent, the calculated ΔE values were found to be 0.297 and 0.355 eV, respectively, as shown in Figure 7(d). The observed increase in ΔE can be attributed to the decreased surface defects and the reduction in nonradiative transitions, effects brought about by Li + doping in the phosphor system.…”

Study on up-conversion luminescence and energy transfer of Tb3+, Yb3+, Er3+ doped Gd2O2S phosphor

“…Rare earth ions have abundant energy levels, which can be used as a medium to realize the transformation of photon frequency and obtain photons of different wavelengths and more uses. So they have a wide range of application value in lighting [1][2][3], laser [4][5][6], communication [7][8][9], biological imaging [10][11][12] and other fields. According to the change of photon frequency, the luminescence of rare earth ions can be divided into down-conversion fluorescence and upconversion fluorescence.…”

Physicochemical Characterization of the Hybrid Molybdate–Tungstate Materials for Solid-State Lighting

“…Suitable hosts for rare earth-based phosphors are known as borates, , alumina, molybdates, − niobates, ,, phosphates, − fluorides, ,− tungstates, − and so on. In the past few years, great attention has been focused on the molybdate–tungstate matrix ,− by virtue of its luminescence and structural properties.…”