Dependence on Ce Concentration of Blue Emission and Crystallographic Properties in SrGa2S4:Ce Electroluminescent Thin Films Grown by Molecular Beam Epitaxy

Abstract
The Ce-doping dependence of blue emission properties has been investigated for SrGa2S4:Ce electroluminescent (EL) thin films grown by molecular beam epitaxy (MBE). EL spectra, EL luminance, photoluminescence (PL) spectra, X-ray diffraction (XRD) intensity, XRD rocking curves, spacing of lattice planes, EL and PL decay times were measured in samples with Ce-doping concentrations ranging from 0.87 mol% to 8.37 mol%. EL luminance reached a maximum at 2.40 mol%. In particular, EL chromaticity remained within the pure blue region even with higher Ce-doping concentrations.