Characteristics of a SrS : Ce thin-film electroluminescent device preparedby post-annealing in H2S

Strontium sulfide doped with cerium (SrS:Ce) thin-film electroluminescent ( TFEL) devices annealed in the presence of H2S are investigated. X-ray diffr action patterns of SrS phosphor layers show a preferential (220) orientatio n, and cerium accumulated in the lower portion of the phosphor in samples a nnealed in H2S. The relative concentrations of S and Sr (S/Sr ratios) of th e phosphors before annealing are thought to be responsible for the EL chara cteristics. Annealing in H2S had a significant effect on the crystallinity of phosphors with low S/Sr ratios before annealing.