Up-Conversion Emissions from HfO: Er, Yb Nanoparticles Synthesized by the Hydrothermal Method.

Up-conversion emission from HfO nanoparticles, as a host lattice, doped with Er and Yb ions and codoped with alkaline cations Li and Na obtained. The HfO nanoparticles, about 80 nm in diameter, were synthesized by the hydrothermal method at 200 °C for 1.3 h, and an additional heat treatment at 1000 °C was necessary to ensure the dopants incorporation into the host lattice.