Effects of site substitutions and concentration on upconversion luminescence of Er(3+)-doped perovskite titanate.

Upconversion photoluminescence (PL) of Er(3+)-doped BaTiO3 (BTO) with perovskite ABO3 structure is studied in terms of Er3+ substitutions for Ba (A-) and Ti (B-site) with different Er3+ doping concentrations. PL quenching with an increase Er3+ doping concentration is investigated based on the structural change and energy transfer of cross-relaxation process in BTO: Er, i.e. (2)H(11/2) + (4)I(15/2) → (4)I(9/2) + (4)I(13/2). Temperature dependence of the PL in BTO: Er is revealed, which is associated with phase transitions of BTO host. The results imply that the emission from substituted Er3+ ions may be used as a structural probe for the ferroelectric titanates.