Plasmonically enhanced upconversion of 1500 nm light via trivalent Er in a TiO2 matrix

Abstract

In this letter, we present a comparative experimental–simulation study of Au-nanodisc-enhanced upconversion of 1500 nm light in an Er3+ doped TiO2 thin film. The geometry of the Au nanodiscs was guided by finite-element simulations based on a single nanodisc in a finite computational domain and controlled experimentally using electron-beam lithography. The surface-plasmon resonances (SPRs) exhibited a well-known spectral red shift with increasing diameter, well explained by the model. However, an experimentally observed double-peak SPR, which resulted from inter-particle interactions, was expectedly not captured by the single-particle model. At resonance, the model predicted a local-field enhancement of the upconversion yield, and experimentally, the luminescence measurements showed such enhancement up to nearly 7 fold from a nanodisc with 315 nm diameter and 50 nm height. The upconversion enhancement agreed qualitatively with the theoretical predictions, however with 3–5 times higher enhancement, which was attributed to scattered light from neighboring particles.

Analytical model for the intensity dependence of 1500 nm to 980 nm upconversion in Er3+: A new tool for material characterization

“…Introducing metallic nanoparticles can enhance the UCL through a resonance phenomenon called a localized surface plasmon, where the incoming light interacts with the metal nanoparticle causing an increase in the near-field around the nanoparticle [9][10][11] . In this way, we have previously obtained a seven-fold enhancement of the upconversion luminescence 12 .…”

Multiscale in modelling and validation for solar photovoltaics

“…Bio-markers and molecular rulers [160] allow to bring photo-active materials such as rare-earths [143], quantum dots [140,142] and dyes close to NP surfaces. Plasmonic field enhancement as well as scattering effects of nanoparticles can be tuned to enhance photon upconversion in rare-earth ions [161], enabling the conversion of two or more low-energy photons into one higher-energy photon, capable of electron-hole-pair generation in the photovoltaic cell [162]. While upconverting materials are generally placed on the back, downshifting or down converting materials can be placed on the front side to lower the energy of high energy (UV) photons and thereby reducing e.g.…”

Enhanced upconversion in one-dimensional photonic crystals: a simulation-based assessment within realistic material and fabrication constraints

“…Therefore, in the unsaturated regime, to which non-concentrated solar illumination belongs [24], the UC efficiency can be increased by light concentration. Besides focusing by conventional means, such as lenses, strong local field enhancements can be achieved through plasmonic structures [25][26][27][28][29][30]. The strong field leads to an increased excitation density in the upconverter and consequently to a higher UC efficiency.…”