Strong Blue, green, and red upconversion emission of Er3+ in sub-microcrystalline BaZrO3:(Yb3+Er3+) is observed. Powder samples were obtained by a facile hydrothermal process at 100ºC with different water to ethanol solvent ratios. The as synthesized nanocrystallites present a stable cubic perovskite phase only for a solvent ratio of 1:1, such behavior is preserved under subsequent annealing treatment up to 1000ºC. A slight phase segregation of rare earth oxides is observed for solvet ratios different of 1:1. Under IR excitation in the range between 900 and 1050nm the Er3+ blue emission was almost not present in single Er3+ doped BaZrO3, whereas it became easily observable when Yb3+ was added as codopant. Besides, both green and red upconversion emission of Er3+ are enhanced by around three orders of magnitude in comparison with the single Er3+ doped BaZrO3. The strong blue emission presents dependence on excitation power, and excitation wavelength, and solvent ratio. A possible mechanism for the upconversion process that leads to the observed blue, green and red emissions under NIR excitation is suggested based on the experimental results.
Journal: TechConnect Briefs
Volume: 1, Nanotechnology 2010: Advanced Materials, CNTs, Particles, Films and Composites
Published: June 21, 2010
Pages: 379 - 382
Industry sector: Advanced Materials & Manufacturing
Topics: Nanoparticle Synthesis & Applications