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

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.

Automated summary

Phosphors for NUV-triggered white LEDs have attracted much attention in recent years. However, it remains challenging to achieve phosphors with high luminous intensity, superior color purity, and excellent thermal stability. In this study, a series of Eu3+-activated alkali rare-earth double-tungstate nanoparticles with high luminescence intensity were prepared using a facile hydrothermal reaction method. The prepared phosphors exhibited superior color purity and excellent thermal stability, and the emission intensity and color purity could be controlled by adjusting the concentration of Eu3+ ions. By utilizing these nanoparticles, a fabricated LED device emitted bright warm white light with a high CRI.