Single-layer gold nanoparticle film enhances the upconversion luminescence of a single NaYbF4: 2%Er3+ microdisk

Harnessing the precious metal plasmon effect is a powerful way to enhance the upconversion luminescence of rare-earth materials, so it has received extensive attention from researchers. In this study, a series of [email protected]2 @NaYbF4: Er3+ composite structures were constructed with an Au mono-layer film (AMF) as the substrates and SiO2 as the isolation layer to enhance the upconversion emission intensity of a single NaYbF4: 2%Er3+ microdisk. When the size of Au nanoparticles was 72 nm and the thickness of the SiO2 isolation layer was 24 nm, the upconversion emission enhancement factor of the single NaYbF4: 2%Er3+ microdisk reached 6.98 under 980 nm laser excitation, due mainly to the enhancement of the local electromagnetic field. The upconversion luminescence properties of a single NaYbF4: 2%Er3+ microdisk were significantly affected by the size of Au nanoparticles, the density of the AMF substrate, and the thickness of the SiO2 isolation layer. The plasmon-enhanced upconversion luminescence mechanism was studied according to its luminescence properties, dynamic tests, and theoretical simulation. The synergistic effects in the local electromagnetic field, luminescence quenching, and local surface plasmon resonance effect are also discussed. The results of this research provide an invaluable theoretical basis for enhancing the upconversion luminescence of rare-earth materials with the help of AMF substrates.