Crystal growth and polarized photoluminescence spectra in Ce-doped single crystal of SrGa2S4

Polarized photoluminescence (PL) spectra were measured in single crystal of SrGa2S4:Ce prepared by chemical vapor transport technique. A PL band with double peaks at 450 and 493 nm showed strong polarization dependence in shapes and intensities between E parallel to c and E perpendicular to c polarizations. The PL spectra have been discussed in the framework of the crystal-field theory by which the two peaks have been assigned to transitions between crystal-field and L-S coupling multiplets of 5d- and 4f-states of Ce3+ in D-4h symmetry. Polarized PL spectra calculated on the basis of the crystal-held theory show good agreement with the experimental ones. From these results we suggest a possibility of controlling the chromaticity in blue electroluminescent (EL) phosphors using epitaxial films with well-defined growth orientation.