Enhanced upconversion emissions of NaNbO3:Er3+/Yb3+ nanocrystals via Mg2+ ions doping

The rod-like NaNbO 3 :Er 3+ /Yb 3+ nanocrystals codoped with Mg 2+ ions were firstly synthesized by hydrothermal method. The effect of Mg 2+ ions on the phase structure and morphology of NaNbO 3 :Er 3+ /Yb 3+ was investigated by XRD and SEM spectra. Addition of Mg 2+ ions enhanced the intensities of green and red UC emissions by about 3 times and prolonged the lifetime of the 4 S 3/2 → 4 I 15/2 transition of Er 3+ ions. The pump power dependences were measured to understand the upconversion mechanism under 980 nm excitation. The tailored local environment of Er 3+ ions by codoping Mg 2+ ions was responsible for the improved optical characteristics of NaNbO 3 :Er 3+ /Yb 3+ /Mg 2+ nanocrystals.