Photo-physical properties of up-converting NaYF4:Yb-Er,Yb-Mn nanocrystals

Sammanfattning: Rare earth-doped upconversion nanoparticles can emit light with various wavelength from ultraviolet to infrared when excited by near-infrared light. The superior properties including long luminescence lifetime, narrow emission spectra, low toxicity and high chemical stability makes it a promising optical material in bioimaging and other applications. This thesis measured and compared the optical properties of NaYF4:Yb-Er and NaYF4:Yb-Mn. with combined AFM-PL measurement applied to identify the single crystal. In addition, the polarization and temperature dependence measurement were also implemented to compare the characteristics. Finally, the errors that may be introduced to the measurement are analysed, and improvements and research plan are proposed and discussed.