Colloidal Lanthanide Nanoparticles: Doping, Epitaxy, and Photon Management

Lanthanides, known as the “vitamin of industry”, have been playing a pivotal role in a wealth of advanced materials and modern technologies including catalysts, magnets, lasers, economical lighting, and solar-energy conversion. With the development of nanoscience, lanthanide nanoparticles have been attracting increasing research interest as a new form of the old materials since 2000. These nanoparticles not only bring properties previously thought impossible in bulk lanthanide materials, but also raise concerns and challenges (e.g. quenching) that were not considered towards practical applications. This dissertation is dedicated to understanding and tackling these challenges with designed colloidal lanthanide nanoparticles. Particularly, the first theme explains how the dopants in the nanoparticle matrix contribute to the size and shape of nanoparticles (doping). The second theme explores the growth behavior of core-shell nanoparticles with controlled interfacial strains (epitaxy). The third theme introduces how to address the quenching challenges and enhance the photoluminescence on nanoparticles with the optimized doping and epitaxy (photon management). We show that the optimized lanthanide nanoparticles have record-high emission efficiency, provide insight for future nanoparticle designs, and can be used as a promising toolset for a wide ranges of research topics including bioimaging, therapeutics, photocatalysis, and optical energy conversion.