%0 Journal Article
%T Multicolor upconversion luminescence of dye-coordinated Er3+ at the interface of Er2O3 and CaF2 nanoparticles
%A Ayaka Hasegawa
%A Ayumi Ishii
%A Miki Hasegawa
%A Miyu Komaba
%A Shuhei Ogata
%A Yuya Adachi
%J Science and Technology of Advanced Materials
%D 2019
%R https://doi.org/10.1080/14686996.2018.1558911
%X ABSTRACT Multicolor upconversion luminescence of Er3+ was successfully enhanced by optimizing the interface in dye-coordinated nanoparticles with a core/shell structure. Red and green upconversion emissions of Er3+ were obtained at the interface of oxide nanoparticles via the intramolecular energy transfer from the coordinating squaraine dye with high light-absorption ability, which was more efficient than emissions through the energy transfer from metal ions such as Yb3+. Additionally, CaF2 nanoparticles as a core material minimized the energy loss with nonradiative downward relaxations in Er3+, resulting in the observation of unusual blue upconversion emissions from the upper energy level of Er3+ by nonlaser excitation using a continuous-wave (CW) Xe lamp at an excitation power of 1.2 mW/cm2. Graphical Abstrac
%U https://www.tandfonline.com/doi/full/10.1080/14686996.2018.1558911