Abstracts

The up-conversion phenomenon occurs when two or more lower-energy photons are added, and one single higher-energy photon is emitted. This phenomenon finds applications in various fields, including bioimaging and solar energy conversion, given its unique non-linear optics. In this work up converting nanoparticles were added to a cellulose ether in order to make mailable and translucent up converting composites and expand on the ever-growing applications of up converting materials.The up-converting material is yttrium fluoride nanoparticles doped with ytterbium and erbium synthesized using a solvothermal method. These nanoparticles were then incorporated into hydroxypropyl methylcellulose (HPMC) films through a drop-casting process and in some cases, gold nanoparticles (AuNps) were also added to enhance the up-conversion emission. X-ray fluorescence nano mapping, conducted at the Carnaúba beamline of the Sirius Synchrotron facility, revealed an intriguing interaction between the upconverting nanoparticles (UCNps) and the AuNps, as well as a unexpected X-ray excited optical emission (XEOL).Furthermore, our photoluminescence study demonstrated an intensified up-conversion phenomenon in the presence of gold nanoparticles.