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.

SUBMITTER: Avram D 

PROVIDER: S-EPMC6303399 | biostudies-literature | 2018 Dec

REPOSITORIES: biostudies-literature