Synthesis of Er³⁺-doped perovskite nanorods with outstanding UC PL behavior

The Er-doped perovskite single-crystal NaNbO₃ nanorods with a series of doping content (0-1 wt%) were successfully synthesized by hydrothermal method. The XRD and Raman analyses indicated that the Er³⁺ ion firstly entered into the B site (Nb⁵⁺) in the ABO₃ perovskite structure and then the A site (Na⁺) with a further increase of Er-doping content. High-resolution transmission electron microscopy (HRTEM) was employed to demonstrate the single-crystal features of NaNbO₃ nanorods. The as-synthesized Er-doped NaNbO₃ nanorods exhibited excellent up-conversion (UC) photoluminescence (PL) behavior. The strong green emission and the weak red emission of Er³⁺ were observed in the UC PL spectra. The maximum emission intensity of the UC PL spectrum was achieved in NaNbO₃ nanorods with 0.5 wt% of Er³⁺ doped. Furthermore, the UC PL spectra obtained under different laser input powers confirmed that two photons contributed to the observed up-conversion luminescence properties. Owing to these luminescent merits, the as-synthesized Er-doped single-crystal perovskite NaNbO₃ nanorods exhibit potential application in novel multifunctional devices.