Spectroscopic properties of Nd3+ ions in nano-perovskite CaTiO3

In this work, we present for the first time the spectroscopic properties of perovskite nanocrystals CaTiO3: Nd3+, measured at room and liquid nitrogen temperature. Samples were prepared by the sol–gel method and annealed at 700 and 1000 °C. The concentration of Nd3+ ranged from 0.5% to 5%. Average nanocrystallite size primarily depends on the annealed temperature and is about 25 and 50 nm for 700 and 1000 °C, respectively. The absorption, emission and excitation spectra (monitored at 1078 nm) as well as the decay time profile of the emission from the 4F3/2 energy level of Nd3+ are obtained. The increasing amount of Nd3+ ions decreases the lifetime of the 4F3/2 level and that changes from 146 μs for 0.5% to 50 μs for 5% of Nd3+ concentration. The strongest emission was observed at two regions: 1050–1120 nm and 865–930 nm and was assigned to the 4F3/2→4I11/2 and 4F3/2→4I9/2 transitions, respectively. The spectroscopic quality parameter of neodymium in the CaTiO3 lattice has been calculated from the emission spectra. The influence of luminescent properties depending on the annealing temperature and concentration of neodymium ions is discussed.