Abstract

Upconversion materials are capable of emitting high-energy photons in the span of ultraviolet to NIR region of electromagnetic spectrum under excitation by low energy NIR photons through a process termed ‘upconversion fluorescence’. The NIR electromagnetic wave has deeper penetration, lower thermal effect, and lower toxicity compared with UV/vis laser, providing UC materials with a wide range of applications. This review focuses on the research progress of the application of UC particles and their role in composite materials, which covers the field of radiation curing technology, anti-counterfeiting technology, photovoltaics, and photocatalysis.

Keywords: Upconversion particles; Light absorption; Energy conversion; Composite materials; Radiation curing; Anti-counterfeiting; Photovoltaics; Photocatalysis