Influence of sintering on photoluminiscent emission of SrS : Cu,Ag powdersand e-beam evaporated phosphor layers

Recently, SrS:Cu,Ag has been studied by several research groups as a blue e mitter for thin film electroluminescent (EL) devices. However, both EL and PL (photoluminescent) spectra of these thin film phosphors suffer from seve re non-reproducibility. In order to solve this problem, the effect of sinte ring the deposition source material (in N-2 and H2S) on the PL characterist ics of both this source material and the deposited thin films is studied. I t will be shown that sintering SrS:Cu,Ag in H2S enhances blue Ag emission i n thin films, which is normally partly quenched at room temperature. Sinter ing also drastically increases the reproducibility of the emission spectra. In order to understand the underlying physical changes, optical and struct ural/morphological characterizations were performed. (C) 2001 Elsevier Scie nce Ltd. All rights reserved.