Multi-zinc oxide-cores@uni-barium sulfate-shell with improved photo-, thermal-, and ambient-stability: Non-equilibrium sorption fabrication and light-emitting diodes application

• Published in: Journal of colloid and interface science 2018-11, Vol.529, p.1-10
• Main Authors: Liang, Ya-Chuan, Liu, Kai-Kai, Wu, Xue-Ying, Lu, Xian-Li, Lu, Ying-Jie, Zhao, Qi, Shan, Chong-Xin
• Format: Article
• Language: English
• Subjects: Light-emitting diodes; mZnO@uBaSO4 nanocomposite; Phosphors
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2018.05.100

Multi-zinc oxide-cores@uni-barium sulfate-shell nanocomposite has been prepared via non-equilibrium sorption process, and the nanocomposite shows improved stability in photo, thermal and ambient aspects. WLED has been fabricated by using the nanocomposite phosphors as down-conversion layer. Thanks to the abundance and eco-friendly property of ZnO, the result reported in this paper may open a promising avenue for healthy WLEDs. [Display omitted] ZnO as an eco-friendly material shows bright luminescence under UV illumination when it is tailored into nanoscale size, which makes it a promising luminescent nanomaterial. However, the poor stability of ZnO hinders its applications drastically. In this work, multi-ZnO-cores@uni-BaSO4-shell (mZnO@uBaSO4) nanocomposite has been prepared through a non-equilibrium sorption process employing ZnO QDs as the “seeds” and BaSO4 as the “valve”. The mZnO@uBaSO4 nanocomposite shows improved photo-, thermal- and ambient-stability compare with bare ZnO QDs. The fluorescence efficiency of the mZnO@uBaSO4 nanocomposite decreases little even after 60 h of UV irradiation compare with ZnO QDs. The mZnO@uBaSO4 nanocomposite shows bright luminescence with little decrease even the ambient temperature up to 160 °C and the nanocomposite shows strong resistance to harsh environment. By coating the mZnO@uBaSO4 nanocomposite and commercial phosphors onto UV-chip, light-emitting diode (LED) with correlated color temperature, Commission Internationale de L'Eclairage coordinate, color rendering index and luminous efficiency of 6109 K, (0.32, 0.33), 85 and 47.33 lm/W have been realized, and this will make a great step towards eco-friendly UV-pumped LEDs.