Contribution to the Problem of Nonstoichiometry in Oxygen-Dominated Phosphors

Abstract

Oxygen‐dominated phosphors of highest efficiencies are generally obtained with nonstoichiometrical compositions. This has been explained with the hypothesis that crystal defects are essential to obtain luminescence. In this paper it is postulated that the ideal, and therefore stoichiometric crystal should have maximum efficiency. The fact that an excess of one of the ingredients in general results in higher efficiency is explained with certain factors arising from the mechanism of the solid‐state reactions, such as the difficulty of reaching equilibrium conditions.