ABSTRACT
The absorption spectra of Tr-like ions with an ns2 ground state configuration, such as In', Sn-' , Sb'' (n=5) and Tl', Bi' (n=6), have been thoroughly studied for 40 years, especially in the field of alkali halide crystals. The spectra of KC1:T1-have been labeled bands A (1 S0-;3131), B ('S0--.'P2), and C (1 S0->'131 ) in the order of increasing energy. However, for the C band in the VUV range, there were no reports of oxygen-dominated lattice phosphors.
