Highly efficient cathodoluminescence of nanophosphors by solvothermal route

Abstract

The low voltage excited nano-size of SrTiO 3: Pr, Al red cathodoluminescent phosphors is successfully prepared by hydrothermal and solvothermal processes. Crystal size does not have obvious growth after post-annealing process under the nucleation seeds control. The nanophosphors synthesized by the solvothermal process have a more stoichiometric and cubic SrTiO 3 structure than the hydrothermal ones. SrTiO 3: Pr, Al nanophosphors synthesized by the solvothermal process with 200 °C/24 h possess a cubic crystal size of about 50 nm. The red cathodoluminescent intensity of 200 °C/24 h-solvothermal phosphors is nine times that of the 250 °C/24 h-hydrothermal ones after 1000 °C/1 h heat treatment. The stoichiometric SrTiO 3: Pr, Al nanophosphors by solvothermal preparation need less amounts of Pr activator and Al dopant than when using conventional solid-oxide preparation and can achieve high cathodoluminescence at a wavelength of 615 nm exciting at a low accelerating voltage of 1 kV. The solvothermal process combined with the post-annealing process to synthesize nanophosphors distributes and excites the activator and the dopant more homogeneously and efficiently in the host structure of SrTiO 3, thus enhancing luminescence.