GREEN LUMINOPHORS IN THE FAMILY OF PHOSPHATES WITH WHITLOCKITE STRUCTURE

Phosphates Ca9Gd1–xTbx(PO4)7 with whitlockite structure are prepared for the first time by the solid-phase method. The obtained compounds are studied by a number of methods such as XRD, second-harmonic generation, luminescence spectroscopy. It is shown that a continuous series of solid solutions up to x = 1.0 is formed. The samples show intense luminescence; the resulting color coordinates belong to the green region. The measured quantum yields exceed those of commercial green phosphors. The processes of luminescence quenching in solid solution are investigated.