Near infrared emission properties of Er doped cubic sesquioxides in the second/third biological windows

Abstract

In the recent years, there is an extensive effort concentrated towards the development of nanoparticles with near-infrared emission within the so called second or third biological windows induced by excitation outside 800–1000 nm range corresponding to the traditional Nd (800 nm) and Yb (980 nm) sensitizers. Here, we present a first report on the near-infrared (900–1700 nm) emission of significant member of cubic sesquioxides, Er-Lu2O3 nanoparticles, measured under both near-infrared up-conversion and low energy X-ray excitations. The nanoparticle compositions are optimized by varying Er concentration and Li addition. It is found that, under ca. 1500 nm up-conversion excitation, the emission is almost monochromatic (>93%) and centered at 980 nm while over 80% of the X-ray induced emission is concentrated around 1500 nm. The mechanisms responsible for the up-conversion emission of Er - Lu2O3 are identified by help of the up-conversion emission and excitation spectra as well as emission decays considering multiple excitation/emission transitions across visible to near-infrared ranges. Comparison between the emission properties of Er-Lu2O3 and Er-Y2O3 induced by optical and X-ray excitation is also presented. Our results suggest that the further optimized Er-doped cubic sesquioxides represent promising candidates for bioimaging and photovoltaic applications.

Metasurface‐Enhanced Photon Upconversion upon 1550 nm Excitation

“…At higher power densities, slope values n = 1.5-1.8 are observed for the red emission of the Er 3+ -doped crystals, which is in agreement with reports from the literature at 1.5 µm laser excitation. [34,35] Also here, similar n values on the metasurface can be obtained at more than one order of magnitude lower excitation power densities P exc than on planar silicon films. These are further indications of enhanced near fields on the metasurface.…”

All near-infrared multiparametric luminescence thermometry using Er3+, Yb3+-doped YAG nanoparticles

“…Therefore, to circumvent this limitation the Yb 3+ co-dopant can be used, which is well known for its high absorption cross section at 10 638 cm À1 as a sensitizer of Er 3+ NIR luminescence. 25,[33][34][35][36] For this study, we have prepared luminescent nanothermometers based on yttrium aluminium garnet (Y 3 Al 5 O 12 , YAG) nanocrystals doped with Yb 3+ and Er 3+ using the modied Pechini method. [37][38][39] YAG is well-known host material which possess high photo resistance, chemical stability, and ease of emission tuning.…”

Structural phase transition, equation of state and phase diagram of functional rare earth sesquioxide ceramics (Eu1−xLax)2O3

“…RE cations over here are in seven fold co-ordinated with the oxygen atoms. As the crystal structure of these oxides is mainly dependent on the cation size, the solid solutions of them are extensively studied to induce or to improve certain physical or chemical properties by using cation size as a tuning parameter 7 – 10 . The structural stability and phase transition as a function of cation size have been studied by many groups and is available in the literature 11 – 14 .…”

“…by using cation size as a tuning parameter [7][8][9][10] . The structural stability and phase transition as a function of cation size have been studied by many groups and is available in the literature [11][12][13][14] .…”