The decay kinetics of visible emissions from Tl centers in Tl-doped halide crystals were studied in a magnetic field, parallel to [001], at temperatures of 0.35 to 0.45K. A previous interpretation of this emission, as being a triplet luminescence of a self-trapped exciton perturbed by a Tl+ ion, was confirmed. However, the detailed structure of the corresponding relaxed excited state was found to be much more complicated than had previously been assumed.

V.Nagirnyi, A.Stolovich, S.Zazubovich, V.Zepelin, G.P.Pazzi: Solid State Communications, 1996, 100[9], 621-4