Stannum-(II) dopant effects on morphology evolution and upconversion performance of Yb3+/Er3+:NaGdF4 crystals

Abstract Hexagonal Yb 3+ /Er 3+ :NaGdF 4 nanocrystals codoped with Sn 2+ ions were prepared via a modulated solvothermal method. Upon introducing 25mol% Sn 2+ ions into the host lattice by substituting Gd 3+ ions, a portion of Yb 3+ /Er 3+ :NaGdF 4 nanocrystals was converted into nanorods. Meanwhile, the upconversion (UC) luminescence intensity of 542 nm and 652 nm were intensified by 24 and 33 times respectively, when compared with samples without Sn 2+ ions doping. The effect of Sn 2+ ions doping content on the morphology and UC emission performances of Yb 3+ /Er 3+ :NaGdF 4 nanocrystals were discussed in detail. The enhancement of UC luminescence intensity could be attributed to the growth of UC nanocrystals and the low crystal local symmetry around Yb 3+ /Er 3+ ion pairs. This study may be beneficial for fabricating high-performance UC materials and realizing their practical applications.