Microwave-assisted hydrothermal synthesis, temperature quenching and laser-induced heating effect of hexagonal microplate β-NaYF4:Er3+/Yb3+ microcrystals under 1550 nm laser irradiation

Rare earth doped materials can usually achieve high efficiency upconversion luminescence (UCL) under high power density infrared laser excitation, in which process the heat generation cannot be avoided, and then induce temperature dependent UCL quenching. This paper dealt with the temperature sensing property and 1550 nm laser irradiation induced thermal effect of Er3+/Yb3+ co-doped NaYF4 microcrystals. The sample was synthesized via a microwave-assisted hydrothermal route, and its crystal structure and microscopic morphology were characterized by means of XRD and FE-SEM. To describe the temperature quenching behaviors for the two typical green emissions of Er3+, a model was proposed and well explained the temperature dependence of two green UCL intensities. Temperature sensing property for NaYF4: Er3+/Yb3+ microcrystals were studied by fluorescence intensity ratio technique, and the temperature sensitivity were also obtained. Furthermore, the 1550 nm laser induced thermal effect was studied, and the result showed that the sample temperature increased with increasing excitation power density. (C) 2017 Elsevier B.V. All rights reserved.