The 4fn energy levels shift due to the van der Waals interaction in the Ln3+ containing luminescent materials

A study about the van der Waals interaction (VDW) between Ln3+ ions and its first neighborhood in luminescent materials is developed. The VDW is responsible for a shift of 4fn energy levels of the order of 102 cm−1. Due to the VDW the higher 4fn energy levels shift more than the lower levels, inducing a redshift in the 4fn-4fn transitions. In this work, the shift of the Lj2S+1 levels is described by the VDW without changes in the free ion or additional parameters.