Accelerated Fabrication and Upconversion Luminescence of Yb3+/Er3+-Codoped CaF2 Nanocrystal by Microwave Heating

Because of the drastic reduction in processing time and energy cost, the microwave radiation applied as an alternative method to synthesize solids has been recently investigated. Yb 3+ /Er 3+ -codoped CaF 2 (CaF 2 :Yb 3+ /Er 3+ ) nanocrystals are fabricated using this approach, and the phenomenon of microwave-enhanced mass transport is observed in this process. The upconversion mechanisms and properties of such nanocrystal have also been studied. Charge compensation and microwave ponderomotive effect are considered as the cause of the specific up-conversion spectrum. This synthesis method and the as-prepared CaF 2 :Yb 3+ /Er 3+ nanocrystal may be potentially useful for advanced phosphor, imaging, anti-counterfeiting labeling, etc.