Upconversion process of NaYF4 Nano Crystals Doped with Ytterbium and Erbium HD

Animation made by Andrew Mueller for researchers at the Molecular Foundry of Lawrence Berkeley Lab National Laboratory. The video shows the unit cell of NaYF4 (green sphere=Na, black=Y, purple=F, yellow=Na/Y) and the crystal structure of a 5 nanometer diameter NaYF4 particle doped with ytterbium and erbium atoms. The animation shows two ytterbium atoms (blue spheres) absorbing consecutive photons of infrared light and transferring their energy to one erbium atom (red sphere). The erbium atom then emits a photon of green light, which is higher in energy than infrared light. Programs Used: Blender, Adobe After Effects --corrected spelling version 2--