“Wet” Chemical Synthesis and Manipulation of Upconversion Nanoparticles

Development of facile synthesis strategies for high-quality lanthanidedoped upconversion nanoparticles with controlled composition, crystalline phase, shape, and size is crucial in tuning their chemical and optical properties and exploring their potential applications in diverse fields. This chapter focuses primarily on the formation mechanism of the crystallization (including nucleation and growth) for monodisperse nanocrystals and various synthetic procedures for the upconversion nanoparticles. Finally, various optical, chemical, and structural characterizations of upconversion nanoparticles are also summarized.