Gap-Plasmon Coupled Nanopillar Array to Promote Upconversion Luminescence

摘要

Upconversion luminescence (UCL) is a nonlinear anti-Stokes process where the two or more photons of near-infrared (NIR) excitation leads to a single photon of visible emission via metastable intermediate excited states.1'2 The NaYF4 inorganic single crystalline host lattice doped with Yb~(3+) and Er~(3+) rare earth trivalent lanthanide ions, NaYF4: Yb~(3+)/Er~(3+), is a typical upconversion (UC) nanophosphors. Despite the fact that the UC own attractive optochemical traits such as substantial anti-Stokes shift, deep tissue penetration, outstanding photostability, the low intrinsic quantum efficiency (QE) of the UC inevitably hinders practical applications.