Design of Interfacial Energy Transfer Model in Upconversion Nanoparticles

The emergence of lanthanide-based upconversion materials provides a feasible solution to the scientific challenges in various fields due to their excellent photon upconversion characteristic and stable physicochemical property. This field benefits greatly from the mechanistic investigation of photon upconversion. In particular, the rational design of interfacial energy transfer (IET) provides a versatile and powerful method to enable and tune the upconversion through precise control of ionic interactions in nanostructures, and further contributes to diversities of frontier applications of upconversion materials. In this chapter, we present a summary and discussion on the design of IET model for upconversion, and demonstrate its unique roles in manipulating energy flux in core–shell nanostructures and mechanistic understanding of ionic interactions on the nanoscale. Its potential in diversities of emerging applications such as information security, upconversion lasers, optical sensing, biological therapy, and lifetime imaging are highlighted. This review would excite new chances for the development of new classes of luminescent materials and further expand their frontier application boundaries.