Influence of Activator Environment on the Spectral Emission of Phosphors

Abstract

The spectral emission of phosphors varies widely with the composition of the basic compound, even under activation by the same element. In any series of isomorphous compounds, however, the variations can be coordinated. They are found to follow a definite rule that is based on corresponding variations in the field strength to which the activator ion is subjected by the anions of its environment. The field strength is shown to depend on the size of the crystal lattice and on the polarizability of the elements composing the crystal.