Monochromatized Xenon Lamp Research Articles

Influence of the ratio of rare earth oxyorthosilicate R2SiO5 (R = La, Y) hosts on the structure and optical properties of co-doped Pr3+ /Dy3+ phosphors

Praseodymium (Pr3+) and dysprosium (Dy3+) co-doped mixed lanthanum/yttrium oxyorthosilicates (La2-xYxSiO5, x = 0.5, 1 and 2) phosphors were synthesized using urea-assisted combustion method. The X-ray diffraction (XRD) patterns showed the pure monoclinic phases of La2SiO5 (x = 0) and Y2SiO5 (x = 2) and mixed phases of La2-xYxSiO5. The diffuse reflectance spectra of the phosphors showed a broad absorption peak with a maximum around 376 nm assigned to O2−→ Pr4+ charge transfer band. The band gaps of the Pr3+/Dy3+ co-doped La2-xYxSiO5 increased from 2.7 to 5.1 eV as the value of x increased from 0 to 2. The luminescent properties were measured when the samples were excited using three different sources, namely 450 W Xenon lamp, 325 He-Cd laser and electron beam. The photoluminescence (PL) emission spectra recorded using monochromatized Xenon lamp showed tunable emission for different excitation wavelengths. For example, when the PL spectra were recorded under 294 nm excitation, using Xenon lamp, emissions from self-trapped excitons (STE) in SiO2, f→f transitions of Dy3+ and Pr3+ were observed. The emission monitored under 349 nm excitation showed the STE peak and the four emission lines of Dy3+. However, when the phosphors were excited using a 325 nm He-Cd laser, the STE emission and four Dy3+ lines were observed in all the samples, but the four manifolds emission from the 1D2→3H4 transition of Pr3+ were only observed for x = 1.5 and 2. Furthermore, the cathodoluminescence (CL) spectra showed the STE band, four emission lines of Dy3+ and four manifolds emission from the 1D2→3H4 transition of Pr3+. The tunable colours of the phosphors were shown in International Commission on Illumination (CIE) coordinate diagram.

Effect of BO33− ions on photoluminescence of CaMoO4:Eu3+ phosphor

A series of CaMoO4-BO33−:Eu3+ phosphors with different concentrations of Eu3+ (0, 0.5, 1.0, 1.5, 2.0, and 2.5 mol. %) were prepared using the solid-state reaction method. The crystal structure, particle morphology, and photoluminescence (PL) were characterized by x-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectrometry, ultraviolet–vis diffuse reflectance, and PL spectroscopy. The XRD patterns showed that CaMoO4−BO33−:Eu3+ phosphor consisted of a pure phase with a tetragonal structure. The introduction of BO33− ions did not affect the crystal structure of the CaMoO4:Eu3+ phosphors, but it slightly influenced the particle morphology and the peak intensity of the red PL from Eu3+. As confirmed from the FE-SEM data, the shapes and sizes of the particles were modified by the incorporation of BO33− ions. The bandgap was influenced by the incorporation of BiO33− and Eu3+ as confirmed from the diffuse reflectance data. The PL intensity was dependent on the concentration of the Eu3+, and the red emission due to the f → f transitions of Eu3+ was enhanced considerably by the incorporation of BO33− ions when the samples were excited at the wavelength of 395 nm using a monochromatized xenon lamp. The effect of BO33− ions on the PL intensity is discussed.

Photoluminescence studies of green emitting BaB8O13: Bi3+ phosphors prepared by solution combustion method

Undoped and bismuth (Bi3+)-doped barium octaborate (BaB8O13) powder phosphors were synthesized by solution combustion method. X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, UV–visible and photoluminescence spectroscopy were used to characterize the phosphors. X-ray diffraction patterns confirmed the formation of orthorhombic phase of BaB8O13. Scanning electron microscopy images showed agglomeration of particles with irregular shapes. The infrared stretching frequencies detected in the spectral wavelength range of 650–1600 cm−1 also confirmed the formation of the BaB8O13 host while the photoluminescence and the energy dispersive X-ray spectroscopy data confirmed the incorporation of Bi3+ ions in the BaB8O13 host lattice. The broad photoluminescence emission due to 1S0–3P1 transitions of Bi3+ ions was observed at 548 nm in the green region of the visible spectrum after exciting the powder phosphors at a wavelength of 271 nm using a monochromatized xenon lamp. The highest photoluminescence intensity was observed from BaB8O13: 0.11Bi3+ with the CIE coordinates of x = 0.3267 and y = 0.6004, suggesting that this phosphor can be used as a source of green light in light emitting devices of different types.

Synthesis, structure and optical studies of ZnO:Eu3+,Er3+,Yb3+ thin films: Enhanced up-conversion emission

ZnO:Eu3+/Er3+/Yb3+thin films were deposited on Si (100) substrates using the sol–gel spin coating technique. The effect of Yb3+ concentration on the structure, particle morphology and optical properties of the films was examined. X-ray diffraction data showed that all the thin films crystallized in a hexagonal wurtzite structure of ZnO. The particle morphology and the distribution of atomic and molecular ionic species on the surface were investigated using scanning electron microscopy and time‐of‐flight secondary ion mass spectrometry, respectively. Atomic force microscopy was used to determine the surface roughness and particle sizes. Photoluminescence (PL) properties of the samples were measured using a mono-chromatized xenon lamp (conventional PL) and a 980 nm laser (up converted PL) as excitation sources. The conventional PL consisted of the normal defect emission. Yb3+ co-doping was found to improve the up converted (UC) PL intensity of both the RE3+ (Eu3+ and Er3+) ion emissions. This was ascribed to two possible energy transfer mechanisms from the 2F5/2 level of the Yb3+ ions to both the excited states of Er3+ and Eu3+ ions through Yb3+ → Er3+ & Er3+ → Eu3+ and Yb3+ → Eu3+ & Yb3+ → Er3+ on an individual behavior. The mechanism of energy transfer from Yb3+ to Eu3+ is explained by simplified energy level diagrams. The diagrams illustrate various defect levels and f-f transitions of the dopant ions. The emission colour was quantified by the standard international commission on illumination (CIE) chromaticity diagram.

Structural evolution induced by substitution of designated molybdate sites (MoO4−2) with different anionic groups (BO3−3, PO4−3 and SO4−2) in CaMoO4:Sm3+ phosphors-A study on color tunable luminescent properties

A series of novel red emitting CaMoO4:Sm3+ (1.0 mol %) phosphors substituted with different anionic groups (BO3−3, PO4−3 and SO4−2) were prepared using a high temperature solid state reaction method. The effects of anionic substitution on the crystalline structure and photoluminescence (PL) properties of the CaMoO4:Sm3+, CaMoO4-BO3:Sm3+, CaMoO4-PO4:Sm3+and CaMoO4-SO4:Sm3+ phosphors were investigated. The structure, particle morphology, chemical composition, vibration modes, and PL properties of the phosphors were investigated by X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectrometry (FT-IR) and PL spectroscopy, respectively. The XRD patterns indicated that the crystalline structures of all the samples were consistent with the standard scheelite structure of CaMoO4. The structural parameters of the pure phase of CaMoO4:Sm3+ phosphor were obtained from the Rietveld analysis. Red PL attributed to the 4G5/2 → 6H9/2 transition of Sm3+ was observed at 646 nm when the CaMoO4:Sm3+ samples were excited by 404 nm using a monochromatized Xenon lamp. Furthermore, orange-red color tunable emission has been achieved by substitution of different anionic groups (BO3−3, PO4−3 and SO4−2) into the CaMoO4:Sm3+ phosphors. Among all the studied phosphors, the CaMoO4-SO4:Sm3+ phosphor showed the strongest PL emission compared to all other phosphors suggesting that it is a promising potential candidate for red emission in the near UV excited white LED applications.

Structure and optical properties of Dy 3+ activated sol-gel ZnO-TiO 2 nanocomposites

Abstract Dysprosium (Dy3+) activated ZnO-TiO2 nanocomposite phosphors were successfully synthesized by the sol-gel method. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared (FTIR), UV–Vis spectroscopy, X-ray photoelectron spectroscopy and photo-luminescent (PL) spectroscopy were used to analyze the structure, morphology, chemical and elemental composition, vibrational bending modes and optical properties of the ZnO-TiO2:Dy3+ nanocomposite phosphors. The XRD patterns confirmed crystallization of wurtzite hexagonal ZnO and tetragonal TiO2 (anatase and rutile) phases. In addition, the XRD patterns showed that secondary phases of ZnTiO3 and Zn2TiO4 were formed. The SEM data showed particle morphology of ZnO-TiO2 nanocomposites consisted of faceted spheres and hexagons which were shown to vary due to incorporation of Dy3+ ions. When excited at 325 nm using monochromatized xenon lamp, the ZnO-TiO2 nanocomposite phosphor exhibited broad emission in the visible region associated with defects in both ZnO and TiO2. The proposed reaction mechanism for ZnO-TiO2 under ultraviolet light irradiation is presented and discussed. The yellowish emission with maximum at ∼587 nm was observed from Dy3+ ions when the nanocomposites were excited at 464 nm using the monochromatized xenon lamp in the blue region of the electromagnetic spectrum.

Structural, optical and photoluminescence properties of Eu3 + doped ZnO nanoparticles

The structure, particle morphology and luminescent properties of europium (Eu3+) doped ZnO nanoparticles (NPs) prepared by co-precipitation method are discussed. When excited using a 325nm He-Cd laser, undoped ZnO NPs exhibited weakly the well-known ultraviolet excitonic recombination emission (at ~384nm) and strongly broad band visible emissions associated with defects (at ~600nm). In addition, the ZnO NPs exhibited green emission at ~600nm associated with defects when excited using a monochromatized xenon lamp. Upon Eu3+ doping line emissions attributed to 5D0→7F1,2,3,4 transitions of Eu3+ ions were observed when the materials were excited using a monochromatized xenon lamp. The exchange interaction mechanism is identified as the cause for concentration quenching of the luminescence of Eu3+ doped ZnO NPs in this study.

The influence of Dy3+ ions concentration and annealing on the properties of LaGdSiO5:Dy3+ nanophosphors

The influence of Dy3+ concentration and annealing on the structure and photoluminescence properties of lanthanum gadolinium oxyorthosilicate (LaGdSiO5) was studied in detail. The X-ray diffraction patterns of the samples annealed at 1000°C for 1h showed new peaks which were not observed in the as-prepared samples. Also some peaks which were in the as-prepared samples were not observed in the annealed samples. These observations suggest that there was phase transformation caused by annealing. The chemical composition and states of the as-prepared and annealed samples were analysed using time of flight secondary ion mass spectroscopy and X-ray photoelectron spectroscopy respectively. The excitation spectra of the as-prepared samples when monitoring the emission at 573nm using a monochromatic xenon lamp showed two peaks located at 227 and 241nm whose intensities varied with the Dy3+ concentration. However, after annealing, the intensity of the 241nm excitation peak decreased drastically. When the emission was monitored at 227 and 241nm, two prominent emission peaks located at 485 and 573nm which were ascribed respectively to the 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions of Dy3+ were observed. When the samples were excited using a 325nm He–Cd laser, an additional broad emission peak was observed around 400 to 460nm which was ascribed to self-trapped excitons (STE) in SiO2. This broad peak decreased after annealing due to reduction in the defects concentration and the subsequent change in the CIE color coordinates. The mechanism of the STE emission is discussed.

Optical properties and chemical composition analyses of mixed rare earth oxyorthosilicate (R2SiO5, R=La, Gd and Y) doped Dy3+ phosphors prepared by urea-assisted solution combustion method

Dysprosium (Dy3+) doped lanthanum gadolinium oxyorthosilicate (LaGdSiO5), lanthanum yttrium oxyorthosilicate (LaYSiO5) and gadolinium yttrium oxyorthosilicate (GdYSiO5) phosphors (in powder form) were synthesized by urea-assisted combustion method. The X-ray diffractometer analysis confirmed that the LaGdSiO5, LaYSiO5 and GdYSiO5 crystalized in monoclinic phases. The chemical composition of the phosphors was analyzed by measuring the atomic and molecular ionic species using the time of flight secondary ion mass spectroscopy (ToF SIMS). In addition, ToF SIMS imaging technique was used to determine the distribution of the Dy3+ dopant ions on the surface on the phosphors. The average crystallite sizes and lattice strains of the phosphor were increased by Dy3+ doping. The field emission scanning electron microscope images showed that the powders were made up of an agglomeration of particles with no regular shape. The photoluminescence data showed narrow line emission peaks at the wavelengths of 485nm (minor emission) and 573nm (major emission) associated with the f→f transitions of Dy3+. The photoluminescence (PL) measurements showed that the emission peak of LaGdSiO5:Dy3+ was ~3× more intense than those of LaYSiO5:Dy3+ and GdYSiO5:Dy3+ when excited using monochromatic xenon lamp with a wavelength of 241nm. However, when the powders were excited using a 325nm He–Cd laser, the highest PL emission intensity was observed from GdYSiO5:Dy3+.

Luminescent properties, intensity degradation and X-ray photoelectron spectroscopy analysis of CaS:Eu2+ powder

In the present work, we report the structure, particle morphology, surface chemical states, photoluminescent properties and cathodoluminescence intensity degradation of the CaS:Eu2+ powder phosphors. X-ray diffraction, X-ray photoelectron spectroscopy, and photoluminescence (PL) spectroscopy data suggest that the powder contains secondary phases that were possibly formed during the preparation or due to unintended contamination. These phases presented an opportunity to demonstrate the dependence of the emission of the Eu2+ ion on the host lattice. An intense red PL broad band with a maximum at 650nm was observed when the powder was excited at 484nm using a monochromatized xenon lamp. When the powder was excited using a 325nm He–Cd laser an additional PL emission peak was observed at 384nm. The origin of this emission is discussed. Auger electron spectroscopy and Cathodoluminescence (CL) spectroscopy were used to monitor the changes in the surface chemical composition and CL intensity of the CaS:Eu2+ phosphors when the phosphor was irradiated with a 2keV electron beam in vacuum. The CL degradation is attributed to, among other things, the formation of a non-luminescent layer of CaSO4, surface charging, and possibly the presence of O defects. This phosphor is evaluated for applications in low voltage field emission displays and light emitting diodes.

TOF SIMS analysis and enhanced UVB photoluminescence by energy transfer from Pr3+ to Gd3+ in Ca3(PO4)2:Gd3+,Pr3+ phosphor prepared by urea assisted combustion

Ca3(PO4)2:Gd3+,Pr3+ phosphors with different concentrations of Gd3+ and Pr3+ were prepared by combustion process using metal nitrates as precursors and urea as fuel. The phosphors were characterized by X-ray diffraction (XRD), Scanning electron microscopy, Time of Flight-Secondary Ion Mass Spectrometry, ultraviolet–visible and photoluminescence (PL) spectroscopies. The XRD patterns were consistent with the standard rhombohedral phase of Ca3(PO4)2 referenced in JCPDS Card No. 70-2065. The average crystallite size calculated using the Scherrer equation at different urea masses was in the range of ∼60–120nm. The PL excitation spectra of Ca3(PO4)2:Gd3+ and Ca3(PO4)2:Pr3+ exhibited peaks at 220–280 and 300–490nm associated with the f→f transitions of Gd3+ and Pr3+ respectively. The ultraviolet B (UVB) emission resulting from the 6P7/2→8S7/2 transition of Gd3+ was observed at 313nm when the Ca3(PO4)2:Gd3+ phosphor was excited at a wavelength of 274nm using a monochromatized xenon lamp. Upon Pr3+ co-doping, the excitation peaks due to Gd3+ and Pr3+ f→f transitions were suppressed and an intense broad excitation peak ascribed to the 4f→4f5d transitions of Pr3+ was observed at 227nm. The peak intensity of the UVB emission at 313nm was shown to improve considerably when the Gd3+ and Pr3+ co-doped systems were excited at the wavelength of 227nm suggesting that the Pr3+ is a good sensitizer of the 313nm narrow line UVB emission from Gd3+.

TOF SIMS analysis and generation of white photoluminescence from strontium silicate codoped with europium and terbium

White light emitting terbium (Tb3+) and europium (Eu3+) codoped strontium silicate (Sr2SiO4) phosphors were prepared by a solid state reaction process. The structure, particle morphology, chemical composition, ion distribution, photoluminescence (PL), and decay characteristics of the phosphors were analyzed by x-ray diffraction (XRD), scanning electron microscopy (SEM), time-of-flight secondary ion mass spectrometry (TOF-SIMS), and PL spectroscopy, respectively. The XRD data showed that our Sr2SiO4 composed of two phases, namely, β-Sr2SiO4 and α′-Sr2SiO4, and the α′-Sr2SiO4 phase was more prominent than the β-Sr2SiO4 phase. The SEM micrographs showed that the particles were agglomerated together and they did not have definite shapes. All ions (i.e., negative and positive) present in our materials were identified by TOF-SIMS. In addition, the chemical imaging performed with the TOF-SIMS demonstrated how the individual ions including the dopants (Eu3+ and Tb3+) were distributed in the host lattice. White photoluminescence was observed when the Sr2SiO4:Tb3+, Eu3+ phosphor was excited at 239 nm using a monochromatized xenon lamp as the excitation source. The phosphor exhibited fast decay lifetimes implying that it is not a good candidate for long afterglow applications.

Tunable and white photoluminescence from Tb3+–Eu3+ activated Ca0.3Sr0.7Al2O4 phosphors and analysis of chemical states by X-ray photoelectron spectroscopy

Tb3+ and Eu3+ activated Ca0.3Sr0.7Al2O4 phosphors with tunable emissions were synthesized via urea assisted combustion method. The phosphors were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy and photoluminescence (PL) spectroscopy. The XRD pattern of the Ca0.3Sr0.7Al2O4:Tb3+, Eu3+ powder showed was composed of a single phase associated with monoclinic SrAl2O4, suggesting that SrAl2O4 was the main structure in the Ca0.3Sr0.7Al2O4 mixed aluminate host and Ca2+ substituted the Sr2+ ions. Consistent with the three dimensional structure of SrAl2O4, the XPS data indicated that there were two different lattice sites occupied by Sr2+ in the lattice and resultantly Ca2+ could also be found at two different lattice sites. Tunable and white PL was generated when the phosphors were optically excited at different wavelengths using a monochromatized xenon lamp. The white PL with the Commission International de L’Eclairage (CIE) coordinates (x=0.343, y=0.325) was a result of the combination of the red line emission from Eu3+ and the blue and green line emissions from Tb3+.

Synthesis and characterization of white light emitting Ca_xSr_1-xAl_2O_4:Tb^3+,Eu^3+ phosphor for solid state lighting

A white light emitting CaxSr1-xAl2O4:Tb3+;Eu3+ phosphor was synthesized by a combustion method using metal nitrates as precursors and urea as a fuel. The X-ray diffraction patterns from the samples showed phases associated with monoclinic structures of CaAl2O4 and SrAl2O4. White photoluminescence with the CIE coordinates (x = 0.343, y = 0.325) was observed when the phosphor was optically-excited at 227 nm using a monochromatized xenon lamp. The white photoluminescence was a result of the combination of blue and green line emissions from Tb3+, and red line emission from Eu3+. The structure and photoluminescence properties of this phosphor are reported.

Promising Zn<sub>3</sub>Ta<sub>2</sub>O<sub>8</sub>:Pr<sup>3+</sup> Red Phosphor for Low Voltage Cathodoluminescence Applications

Zn3Ta2O8 is a promising host for low voltage cathodoluminescence (CL) applications. Surface chemical stability during low voltage electron beam excitation is a prime concern for phosphors to be used in various new generation information displays. Photoluminescence (PL) and CL characteristics of the Zn3Ta2O8 host doped with Pr3+ are presented. The phosphors were synthesized via solid-state reaction route at 1100°C. Red CL or PL with a maximum at 611 nm, attributed to the 1D2-3H4 transition of the Pr3+ ion, was observed at room temperature under high energy electron (2 keV, 12 μA) or a monochromatic xenon lamp (257 nm) irradiation. Electron stimulated chemical changes on the surface of the Zn3Ta2O8:Pr3+ phosphor during an electron beam exposure from 0-350 C/cm2 was monitored using Auger electron spectroscopy. The CL exhibited only a 20% loss in the original intensity during the continuous electron beam exposure. X-ray photoelectron spectroscopy (XPS) was used to estimate the redox states of the chemical constituents and a comparison of binding energies was made with the standard Ta2O5 and ZnO compounds. A correlation between the structural configuration of Zn3Ta2O8 and the XPS data is also established.

Luminescence characterization and electron beam induced chemical changes on the surface of ZnAl2O4:Mn nanocrystalline phosphor

Luminescence characteristics and surface chemical changes of nanocrystalline Mn2+ doped ZnAl2O4 powder phosphors are presented. Stable green cathodoluminescence (CL) or photoluminescence (PL) with a maximum at ∼512nm was observed when the powders were irradiated with a beam of high energy electrons or a monochromatic xenon lamp at room temperature. This green emission can be attributed to the 4T1→6A1 transitions of the Mn2+ ion. Deconvoluted CL spectra resulted in two additional emission peaks at 539 and 573nm that may be attributed to vibronic sideband and Mn4+ emission, respectively. The luminescence decay of the Mn2+ 512nm emission under 457nm excitation is single exponential with a lifetime of 5.20±0.11ms. Chemical changes on the surface of the ZnAl2O4:Mn2+ phosphor during prolonged electron beam exposure were monitored using Auger electron spectroscopy. The X-ray photoelectron spectroscopy (XPS) was used to determine the chemical composition of the possible compounds formed on the surface as a result of the prolonged electron beam exposure. The XPS data suggest that the thermodynamically stable Al2O3 layer was formed on the surface and is possibly contributing to the CL stability of ZnAl2O4:Mn phosphor.

Luminescent properties of Ca 0.97Al 2O 4:Eu 0.012+,Dy 0.023+ phosphors prepared by combustion method at different initiating temperatures

Ca 0.97Al 2O 4:Eu 0.01 2+,Dy 0.02 3+ powder phosphors were prepared by combustion method at different initiating temperatures (500–800 °C) using urea as a fuel. As confirmed by the X-ray diffraction (XRD) data, the powders crystallized in well known monoclinic phases of CaAl 2O 4, with traces of incidental impurities. Observed from the scanning electron microscopy (SEM) images were porous particles with irregular shapes and sizes and there were a lot of voids, which is a true reflection of the inherent nature of the combustion process. The PL spectra, recorded when the powders were excited by a 325 nm He–Cd laser at room temperature, showed broad blue emission with a maximum at 449 nm. This emission can be ascribed to 4f 65d 1 to 4f 7 transition of the Eu 2+ ions. The maximum PL intensity was recorded from the sample prepared at the initiating temperature of 600 °C. Consistent with the PL emission data, the longer decay time was recorded from the same sample using Cary Eclipse spectrophotometer fitted with a monochromatized xenon lamp. The effect of initiating combustion temperature on the crystalline structure and PL intensity was investigated.

Photoluminescence properties of SrAl2O4:Eu2+,Dy3+ thin phosphor films grown by pulsed laser deposition

Thin films of SrAl2O4:Eu2+,Dy3+ phosphor were deposited on silicon [Si (100)] substrates using a 248 nm KrF pulsed laser. Deposition parameters, such as substrate temperature, pulse repetition rate, number of laser pulses, and base pressure, were varied during the film deposition process. Based on the x-ray diffraction data, all the films were amorphous but were emitting visible light when excited by a monochromatic xenon lamp. The chemical composition and the stoichiometry of the films determined by the Rutherford backscattering spectroscopy were consistent with the commercial SrAl2O4:Eu2+,Dy3+ powder used to prepare the films. Photoluminescence (PL) emission spectra of the films were characterized by major green emission with a maximum at ∼520 nm and minor red emission with a maximum at 630 nm. The green and red photoluminescence at 520 and 630 nm are associated with the 4f65d→4f7(S87/2) and D50-F72 transitions of Eu2+ and residual Eu3+ ions, respectively. Brighter films were shown to have relatively higher values of the root mean square surface roughness, which were determined from the atomic force microscopy data. The effects of processing parameters on the PL intensity are discussed.

The influence of the number of pulses on the morphological and photoluminescence properties of SrAl2O4:Eu2+,Dy3+ thin films prepared by pulsed laser deposition

The current work reports on the influence of the number of laser pulses on the morphological and photoluminescence properties of SrAL 2 O 4 :Eu 2+ ,Dy 3+ thin films prepared by the pulsed laser deposition (PLD) technique. Atomic force microscopy (AFM) was used to study the surface topography and morphology of the films. The AFM data showed that the film deposited using a higher number of laser pulses was packed with a uniform layer of coarse grains. In addition, the surface of this film was shown to be relatively rougher than the films deposited at a lower number of pulses. Photoluminescence (PL) data were collected using the Cary Eclipse fluorescence spectrophotometer equipped with a monochromatic xenon lamp. An intense green photoluminescence was observed at 517 nm from the films prepared using a higher number of laser pulses. Consistent with the PL data, the decay time of the film deposited using a higher number of pulses was characteristically longer than those of the other films. The effects of laser pulses on morphology, topography and photoluminescence intensity of the SrAl 2 O 4 :Eu 2+ ,Dy 3+ thin films are discussed.