On the character of the optical transitions in closed-shell transition metal oxides doped with Bi3+

Abstract

A criterion is introduced to achieve the assignment of the optical features observed in the excitation spectra of Bi³⁺ ions incorporated in closed-shell transition metal oxides. The model is based on the calculation of the energy associated with the lowest ¹S₀ → ³P₁ intra-ionic transition of Bi³⁺ (A-like transition), the metal-to-metal charge transfer (D-like transition) and the Stokes shift of the corresponding emission.