Emission, excitation and polarization spectra, and luminescence decay, were studied in Tl-doped crystals. The spectral bands of complicated Tl centers were analyzed, and a 2.75eV emission was attributed to triplet emission from dimer Tl+Tl+ centers. A similar emission band was found in polycrystalline layers.

Luminescence of Complicated Thallium Centers in CsI:Tl. V.Babin, A.Krasnikov, H.Wieczorek, S.Zazubovich: Nuclear Instruments and Methods in Physics Research A, 2002, 486[1-2], 486-9