Yb super(3+) concentration dependence of upconversion luminescence in Y sub(2)Sn sub(2)O sub(7):Yb super(3+)/Er super(3+) nanophosphors

• Published in: Journal of materials science Vol. 49; no. 17; pp. 6081 - 6086
• Main Authors: Liao, Jinsheng, Nie, Liling, Liu, Shaohua, Liu, Bao, Wen, He-rui
• Format: Journal Article
• Language: English
• Published: 01.09.2014
• Subjects: Biomedical materials; Cross relaxation; Emission; In vivo testing; Luminescence; Nanostructure; Pyrochlores; Upconversion
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-014-8334-9

Pyrochlore Y sub(2)Sn sub(2)O sub(7) nanophosphors codoped with Er super(3+) (fixed 2 at.%) and Yb super(3+) ions (2-16 at.%) were synthesized via hydrothermal process followed by heat treatment. We investigate the infrared-to-visible upconversion (UC) luminescence properties of Er-Yb codoped Y sub(2)Sn sub(2)O sub(7). Upon 980 nm excitation at room temperature, green (at ~522 and 544 nm) and red (at ~661 nm) UC emissions were observed, which are ascribed to the ( super(2)H sub(11/2), super(4)S sub(3/2)) arrow right super(4)I sub(15/2) and super(4)F sub(9/2) arrow right super(4)I sub(15/2) transitions, respectively. It has been found that the Yb super(3+)-doping concentrations have greatly influenced on the UC luminescence intensity and the emission ratio of the red and green in Y sub(2)Sn sub(2)O sub(7):Yb super(3+)/Er super(3+) nanophosphors. The tunable emission is due to the energy back transfer from Er super(3+) to Yb super(3+) and the cross relaxation between the two neighboring Er super(3+) ions. It is expected that the achieved single and intense red emission band may have potential application for in vivo bioimaging.