Introduction of Lanthanide Luminescence

Lanthanide elements are located in Period 6 in periodic table. The elements in lanthanide group are defined as fourteen elements (Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu). The smallest element Ce and the largest element Lu have one and fourteen electrons in 4f orbital, respectively. The electrons in 4f orbital provide characteristic luminescence properties of lanthanide elements. In the first chapter, fundamental electron configuration and transitions are based on the 4f orbital in luminescent lanthanide ions. The 4f-4f transition probability based on the Laporte forbidden without parity change is much smaller than those of corresponding luminescent molecules and transition-metal phosphor. The Laporte forbidden without parity change is also explained using the Judd-Ofelt parameter.