Optical temperature sensing behavior of enhanced green upconversion emissions from Er–Mo:Yb₂Ti₂O₇ nanophosphor

• Published in: Sensors and actuators. B, Chemical Vol. 159; no. 1; pp. 8 - 11
• Main Authors: Cao, B.S, He, Y.Y, Feng, Z.Q, Li, Y.S, Dong, B
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 28.11.2011
• Subjects: Actuators; emissions; Energy transfer; Excitation; fluorescence; molybdenum; Nanocomposites; nanocrystals; Nanomaterials; Nanostructure; Phosphors; sol-gel processing; temperature; Upconversion
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2011.05.018

The Er–Mo:Yb₂Ti₂O₇ nanocrystalline phosphor has been prepared by sol–gel method and used as an optical thermometry. By Mo codoping, the green upconversion (UC) emission intensity increased about 250 times than that of Er:Yb₂Ti₂O₇ under a 976nm laser diode excitation. It indicates that such green enhancement arises from the high excited state energy transfer (HESET) with the |²F₇/₂, ³T₂> state of Yb³⁺–MoO₄ ²⁻ dimer to the ⁴F₇/₂ level of Er³⁺. The fluorescence intensity ratio (FIR) of the two green UC emissions bands was studied as a function of temperature in a range of 290–610K, and the maximum sensitivity and the temperature resolution were approximately 0.0074K⁻¹ and 0.1K, respectively. It suggests that the Er–Mo:Yb₂Ti₂O₇ nanophosphor with a higher green UC emissions efficiency is a promising prototype for applications in optical temperature sensing.