Near-IR luminescence from subvalent bismuth species in fluoride glass

The broadband NIR luminescence of subvalent bismuth species was demonstrated in partially reduced ZrF4–BiF3–NaF and ZrF4–BiF3–BaF2 fluoride glasses. The parameters of luminescence were reported and compared with luminescence from other bismuth-doped materials. Since fluoride glass compositions are based on strong Lewis acids (ZrF4 in present case) they can stabilize NIR photoluminescent subvalent bismuth species.

► Fluoride glasses can stabilize NIR luminescent subvalent bismuth species.
► Subvalent bismuth species formed during reduction of bismuth containing fluoride glass.
► Only one subvalent bismuth compound caused NIR luminescence in fluoride glass.