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

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.