Impurity trapped excitons under high hydrostatic pressure

Abstract Paper summarizes the results on pressure effect on energies of the 4f n → 4f n and 4f n −1 5d 1 → 4f n transitions as well as influence of pressure on anomalous luminescence in Ln α+ doped oxides and fluorides. A model of impurity trapped exciton (ITE) was developed. Two types of ITE were considered. The first where a hole is localized at the Ln α+ ion (creation of Ln (α+1)+ ) and an electron is attracted by Coulomb potential at Rydberg-like states and the second where an electron captured at the Ln α+ ion (creation of Ln (α−1)+ ) and a hole is attracted by Coulomb potential at Rydberg-like states. Paper presents detailed analysis of nonlinear changes of energy of anomalous luminescence of Ba x Sr 1− x F 2 :Eu 2+ ( x > 0.3) and LiBaF 3 :Eu 2+ , and relate them to ITE-4f 6 5d 1 states mixing.