Up-conversion luminescence and defect structures in Sc: Dy: LiNbO3 crystals affected by Sc3+ concentration

Abstract

Up-conversion luminescent material LiNbO3 crystal has been studied intensively due to its applications in solar cells, medical applications, color displays and so on. LiNbO3 crystal with poor ability of photodamage resistance limits its application in practice. Up-conversion luminescence properties of Dy: LiNbO3 crystals doped with anti-optical damage dopants have a promising future. Four Sc: Dy: LiNbO3 crystal samples were prepared by the Czochralski technique with Sc3+ concentrations of 0, 1, 2, and 3 mol%. Effective concentrations of Sc3+ and Dy3+ in the crystals were measured by ICP-AES. The occupancy rate of the dopant and crystal structure were investigated by XRD and IR transmission spectra. The properties of up-conversion emission were studied in view of up-conversion emission intensity and fluorescence lifetime. Blue (474 nm), yellow (583 nm), and red (655 nm) up-conversion luminescence were achieved under 800 nm excitation. Remarkably, the luminescence intensity increases significantly by several times when the Sc3+ doping concentration was 3 mol%. This indicates that Sc: Dy: LiNbO3 crystals have potential as optical devices.