Luminescence and crystallinity enhancement using nano-oxide

The seeded nano-TiO2 particles in the hydrothermal (HT) solution assist phosphor crystallite nucleation and growth, facilitate formation of cubic grain shape, but limit grain growth during post-annealing so as to strongly enhance the cathodoluminescence (CL) intensity. Nano-crystallites of SrTiO3:Pr, Al phosphors approximately 80 nm with specific shape are successfully obtained and red cathodoluminescence is easily excited at low accelerating voltage of 1 kV. The obtained phosphors after annealing at 1000 °C 1 h−1 exhibit the highest CL intensity than those obtained under other annealing conditions and those direct-pyrolyzed phosphors as well as mixed-oxide (MO) phosphors having composition similar to hydrothermal ones. The smaller phosphor crystal possesses larger surface and homogeneous activators distribution to facilitate the efficient excitation of low-energy electron bombardment of 1 keV.