Quantum-Cutting Phosphors and Their Application in Green Lighting

摘要

The principle of quantum cutting (QC), QC phosphors, and experimental instrumentations are introduced and reviewed in the article. Recently, intensive research activity has been focused on QC by down conversion mechanism in rare-earth-doped phosphors in the vacuum ultraviolet (VUV) spectral region, mainly because VUV-excited phosphors are indispensable for applications of plasma display panels (PDP) and mercury-free lighting. With proper design by integrating rare earth ions into appropriate host matrix materials, the quantum efficiency of QC phosphors can reach in principle up to 195% (i.e., LiGdF{sub}4:Eu) and 194% (i.e., BaF{sub}2:Gd, Eu), respectively. Furthermore, the research on QC phosphors generally requires light source such as synchrotron radiation. The QC phosphor K{sub}2GdF{sub}5:Tb{sup}(3+) is used herein as an example to illustrate the investigation of VUV spectroscopy, mechanism of QC, and the quantum efficiency as a function of Tb{sup}+ dopant content.