Temperature dependence of luminescence properties of praseodymium-doped perovskite CaTiO3:Pr3+

A polycrystalline perovskite CaTiO3:Pr3+ was synthesized and the temperature dependence of luminescence properties was investigated in the temperature range of 6–440 K. CaTiO3:Pr3+ exhibits red emission ascribed to the f–f transition from the excited state 1D2 to the ground state 3H4 of Pr3+ upon the band gap photo-excitation between valence and conduction band, and upon the IVCT (inter valence charge transfer between Pr3+ and Ti4+) photo-excitation. Below 330 K, the emission intensity upon the band gap excitation increased with temperature, while the temperature dependence of emission intensity upon the IVCT excitation is relatively small, indicating that the electron transfer process between Pr3+ and the host accompanied by the band gap excitation is thermally activated. Above 330 K, the thermal quenching of emission was observed upon both of the band gap and the IVCT excitation and the energy barrier for thermal quenching was estimated to be ∼5500 cm−1.

► Temperature dependences of luminescence properties of CaTiO3:Pr3+ as red phosphor.
► Below 330 K, the emission intensity upon the band gap excitation increased with temperature, indicating that the electron transfer process between Pr3+ and the host accompanied by the band gap excitation is thermally activated.
► Above 330 K, the thermal quenching of emission with the energy barrier of ∼5500 cm−1 was observed.