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The photo- and cathodoluminescence properties of epitaxial lithium-doped zinc gallate thin-film phosphors grown on (100) MgO single crystal substrates using pulsed laser ablation were investigated. The addition of lithium to both undoped and Mn-doped ZnGa[sub 2]O[sub 4] films significantly enhanced the photo- and low-voltage cathodoluminescent intensity. Cathodoluminescent efficiencies for as-deposited undoped and Mn-doped lithium zinc gallate films as high as 0.21 1m/W and 0.29 1m/W, respectively, were achieved for 1 kV and 2.26 µA/cm[sup 2]. Based on these results, lithium-doped zinc gallate thin-film phosphors appear to be attractive for applications in low-voltage field emission display devices. [ABSTRACT FROM AUTHOR]

Describes the synthesis and characterization of SrS:Te powders which were found to have two high energy emission bands under photoluminescent excitation. Determination of the processes responsible for luminescence; Information on temperature quenching activation energy; Radiative recombination rate of TeS and TeS-TeS bound excitons; Conclusion reached on the description.

Experimental studies of Lu2 SiO5 : Ce (LSO:Ce) crystals codoped with various concentrations of Ca (0,0.1,0.2,0.3, and 0.4 at% in the melt) are presented. The scintillation and optical properties including photoluminescence decay, emission, excitation, absorption, afterglow and thermoluminescence properties are investigated as a function of Ca concentration. Experimental data show Ca codoping significantly reduces the trapped charge population in the crystal matrix. Hence, the scintillation decay time of LSO:Ce is shortened and the afterglow is suppressed. Thermoluminescence studies show a strong correlation between the integrated thermoluminescence intensity and the Ca concentration. [ABSTRACT FROM AUTHOR]

Orthorhombic epitaxial Sr[sub 2]CeO[sub 4] thin-film phosphors were grown on (100) SrTiO[sub 3] and yttria-stabilized-zirconia (YSZ) single crystal substrates with epitaxial relationships of (100) [010][sub Sr[sub 2]CeO[sub 4]]//(100)[010][sub SrTiO[sub 3]] and (100)[010][sub Sr[sub 2]CeO[sub 4]]//(100)[011][sub YSZ], respectively. As-deposited films exhibit a broadband photoluminescence (PL) emission, peaking at about 477-481 nm with a maximum cathodoluminescence (CL) intensity at about 465 nm. Enhanced PL intensity was observed for the films deposited on (100) YSZ and SrTiO[sub 3] substrates as compared to deposits on c-plane sapphire substrates, correlating with improved intragranular crystallinity and reducing defects via epitaxy. Postannealing in air significantly enhanced both of the PL and CL intensities. Luminous efficiency of 0.14 lm/W at 1 kV and 22 μA/cm[sup 2] was observed for a 2-μm-thick film annealed at 1000 °C in air. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Abstract: Lutetium oxyorthosilicate (LSO) thin films with a cerium thickness gradient were sputter deposited to investigate the optimum cerium concentration for emission intensity. Thin film cerium concentration ranged from 0.06 to 0.88at%. To compare the thin film samples to single crystal LSO, a set of single crystal LSO samples were investigated with cerium concentrations of 0.0015, 0.0095 and 0.078at%. The thin film samples showed peak photoluminescence emission intensity at a cerium concentration of 0.35at%; however, the single crystal samples exhibited peak photoluminescence emission intensity at a lower cerium concentration of 0.0095at%. The photoluminescence excitation and emission spectra as a function of concentration demonstrate the concentration quenching behavior and the mechanisms are speculated to be due to radiative (self-absorption) and non-radiative energy transfer, which may be phonon assisted. [Copyright &y& Elsevier]