Fabrication of CaS : Pb blue phosphor by incorporating dimeric Pb2+ luminescent centers

The CaS:Pb phosphor emitting blue electroluminescence (EL) induced by dimer ic Pb2+ luminescent centers was deposited using the controlled atomic layer deposition technique. The effect of the incorporation method and concentra tion of Pb2+ ions on the color of high luminance CaS:Pb phosphor was invest igated at the deposition temperatures of 350 and 400 degreesC. The blue EL emission at 440-445 nm could be maintained with the Pb concentration rangin g from 0.6 to 2.5 mol % contrary to the earlier works that had demonstrated very sensitive dependence of color on Pb2+ concentration. The selective in corporation of dimeric Pb2+ ions was attributed to the reactivity of tetrae thyl lead as Pb precursor as well as the controlled deposition technique. ( C) 2001 American Institute of Physics.