Synthesis Protocol of Upconversion Nanoparticles

Multifunctional upconversion nanoparticles (UCNPs), which consist of a host matrix and dopants, are capable of converting low-energy photons into high-energy photons. Nanoparticles can be prepared by different synthesis techniques, viz, sol–gel, coprecipitation, hydrothermal, thermolysis, etc. Controlling different synthesis parameters including reaction time, temperature, pH, nature of the solvents used, etc., are very much important in order to achieve monodisperse UCNPs. This chapter deals with the detailed discussion of involved methodology as well as the recent advancement of some typically used synthesis strategies.