Rationally-designed core-shell structure with double-plasmon effect for efficient and tunable upconversion luminescence emission

Rare earth-doped upconversion luminescence has great potential toward modern anti-counterfeiting applications. The coupling effect between low-cost plasmonic semiconductor nanostructures could enhance the local electric field of the surrounding material, thereby improving the light absorption of the system. Considering both light absorption and emission aspects, we propose a technological approach to combine core-shell structures and plasmon resonance for synergistically enhancing the luminescence intensity with tunable upconversion luminescence emission. As a result, the luminescent intensity of rationally-designed core-shell structure with doubleplasmon effect has been elevated by two orders of magnitude than that of only core-shell structure, and its selectivity of the tricolor luminescence has been improved significantly, representing the importance to be serviced as highly-efficient color-tunable anti-counterfeiting materials.