Lanthanide-doped phosphor: an overview

The hunt for energy-efficient solid-state materials for lighting and other display application took enormous pace in the past few decades. Phosphors have come up as the material of choice for these purposes due to their unique and unrivalled features like high emission quantum efficiency, well-defined narrow spectral pure emission, and high eco-friendliness characteristics. These materials are meant to meet the various needs of this century, which is riding on rapid advancement in optoelectronic devices. This chapter aims to revisit and discuss in detail some of the most widely used lanthanide rare-earth (RE) ions from the perspective of RE ions as an activator and a sensitizer in doped materials and possible transitions within their energy levels. Here, we have also discussed the effect of various hosts on the optical emission properties of RE ions and their application in light-emitting diodes (LEDs).