Emission properties of GdOBr:: Ce3+ and Tb3+ phosphors

The present investigation aims to elucidate the photoluminescent behavior of luminescent powder phosphors of GdOBr:Ce3+ and GeOBr:Tb3+ prepared by a solid state reaction method. Their emission properties have been systematically investigated. Photo luminescence have revealed a bright and broader (320-480 nm) violet-blue color emission (FWTM=85 nm) from the Ce3+ (5d(D-2) --> F-2(5/2)) and an intense and sharp (543 nm) green color emission (FWHM=5 nm) from Tb3+ (D-5(4) --> F-7(5)) phosphors as well as three other weaker emission transitions D-5(4) --> F-7(6,4,3) at 485, 582 and 619 nm. Under a UV source, a very bright green emission color has been observed from terbium phosphor and a strong bluish violet color from cerium phosphor. The emission color richness defining CIE coordinates have been evaluated for these blue-violet (x = 0.155, y = 0.008) and green (x = 0.285, y = 0.554) luminescent powder phosphors. (C) 2002 Published by Elsevier Science B.V.