Efficiency improvement of up-conversion process of plasmonic-enhanced Er-doped-NaYF₄ nanoparticles under IR excitation

Abstract

The up-conversion process is extensively studied because of its wide variety of applications such as bioimaging, energy harvesting, and optical sensors. However, the optical conversion efficiency is still relatively low and needs to be improved. Therefore, this paper introduces a detailed study of improving the up-conversion emission efficiency through adding plasmonic metallic nanostructures to the up-conversion optical centers. Our idea is to couple the optical plasmonic resonance with the visible emission of the optical centers under IR excitation. The optical centers are erbium ions hosted by fluoride low-phonon environment. Our calculations consider most possible transitions that can occur between the optical centers; tri-valent erbium ions, through Judd-Ofelt analysis. In addition, the effect of changing some parametric values is discussed, such as irradiance, and multi-phonon relaxations, to show their optimum values which correspond to best quantum yield efficiency. By increasing the diameter of added gold nanoparticles (Au NPs), the probability of occupation has been increased, and consequently, both the luminescence and up-conversion efficiency have been increased.

Resonant Control and Enhancement of Upconversion Luminescence of NaYF4:Yb,Er Nanoparticles on Metal Gratings

“…[ 40,41 ] Besides, UCL color of Ln 3+ ‐doped materials can be controled by tunning the SP resonance positions, as experimentally reported by us based on a Fabry–Perot cavity, [ 42 ] and theoretically studied by others recently. [ 43–45 ] Note that, in many applications, multicolor UCLs of the Ln 3+ ‐doped nanomaterials are unnecessary; instead, single‐color UCL with stronger intensity is more desirable. [ 20,46 ]…”

“…[40,41] Besides, UCL color of Ln 3+ -doped materials can be controled by tunning the SP resonance positions, as experimentally reported by us based on a Fabry-Perot cavity, [42] and theoretically studied by others recently. [43][44][45] Note that, in many applications, multicolor UCLs Large plasmonic enhancements of upconversion luminescence (UCL) of lanthanide-doped materials are achieved usually by plasmon resonances at excitation wavelengths. Here, moderately high-Q plasmon resonance modes at emission wavelengths are used to control and enhance the UCLs of NaYF 4 :Yb,Er nanoparticles on metal gratings.…”

Regulative control and enhancement of multi-color upconversion luminescence with DBR cavities

“…Ln 3+ -doped materials usually have multiple color of UCL emission bands. By tuning resonance position of the cavity mode, one color of the UCL emissions will be particularly enhanced, or relative ratio of multi-color UCL intensities will be modified [28][29][30][31]. Note that, in many applications, the multi-color UCL are unnecessary; instead, single-color UCL with stronger intensity is more desirable [20,32].…”

Decay Rates of Plasmonic Elliptical Nanostructures via Effective Medium Theory

“…Moreover, the metallic nano-radiator quantum dot can be employed as an amplifier to the plasmonic surface by using the emission radiation [29,30]. The plasmonic metallic nanostructures; such as gold, silver, and copper can be embedded in many applications such as solar cells [31][32][33][34][35][36], up conversion [32,[37][38][39], light emitting diodes (LEDs) [40,41], lasers and laser printing [42][43][44][45], sensors and photodetectors [46][47][48][49]. Moreover, the plasmonic nanoparticles aid to slow down the speed of light which can enhance both absorption efficiency and optical coupling in the waveguide-cavity for optical communication networks and sensing applications [25,[48][49][50][51][52][53].…”