MICROSTRUCTURAL CHARACTERIZATION AND PHOTOLUMINESCENCE OF SRGA2S4-CE3-FILMS GROWN BY DEPOSITION FROM BINARY VAPORS( THIN)

Detailed investigations of the microstructural properties of SrGa2S4:C e3+ thin films grown by deposition from binary vapors (DBV) were carri ed out by X-ray diffraction analysis (XRD), energy dispersive X-ray di ffraction measurements (EDX), electron probe microanalysis (EPMA), and X-ray photoelectron spectroscopy (XPS) depth profiling. The results i ndicate uniform distribution of the constituent elements in the nearly stoichiometric structure of the thin films. Photoluminescence (PL) da ta including absorption and luminescence spectra in the temperature ra nge of 10 to 300 K and decay characteristics show that an increase in Ce concentration from 0.2 to 3 mol% is accompanied with a marked incre ase in both the intensity of activator absorption and decay time, whil e the emission and excitation bands remain fixed in position. A mechan ism involving the concentration-dependent interactions between differe nt centers in the lattice is proposed, which may explain the experimen tally observed behavior.