Photoluminescence (PL) properties of NaLi2PO4:Eu3+ phosphor for solid state lighting application

The polycrystalline NaLi2PO4:xEu (x=0.001,0.002,0.005,0.01 and 0.02) phosphors were successfully synthesized via modified solid state diffusion method [MSSDM]. The structural of prepared phosphor was confirmed by using XRD (X-ray diffraction) technique. Additionally, the photoluminescence (PL) behaviors of NaLi2PO4:xEu phosphor was studied.The XRD pattern of prepared phosphor is well matched with JCPDS file.The PL excitation of prepared phosphor was monitored at 618nm while emission was monitored at 393 nm. The effect of different concentrations of Eu3+ ions in NaLi2PO4 phosphor was studies and optimum PL intensity was obtained at x=0.005 mol. of Eu3+ ion. The CIE co-ordinates were calculated and obtained in orange- red region.

Studies on the photoluminescence and thermoluminescence properties of CaZrO3:xEu3+ phosphor for dosimetric application

Series of CaZrO3:xEu3+ (x=0.01, 0.02, 0.03, 0.04 and 0.05) phosphors have been prepared by low temperature sol-gel auto combustion method. The structure and morphology of the samples were investigated by X-ray diffraction (XRD) and field-emission scanning electron microscope (FE-SEM). The energy-dispersive X-ray spectroscope (EDX) was employed to analyze the elemental composition of the phosphor. The XRD patterns indicated that the sample was single phase at 350 ◦C with a perovskite structure. The optimum temperature for the single- phase and crystalline phosphors of CaZrO3:xEu3+ was 700 ◦C. Study of photoluminescence (PL) at room temperature showed that the phosphors can be excited by light with a wavelength of 391 nm. The results of emission spectrum showed that the red luminescence of CaZrO3:xEu3+ due to electric dipole transition of 5D0→7F2 was dominant at wavelength of 615 nm and weaker transition at wavelength of 590 nm which was due to magnetic dipole transition of 5D0→7F1. For the thermoluminescence (TL) study the prepared sample irradiated by X-ray lamp, the TL curve was then recorded at fixed heating rate of 2 ◦C/s. The TL glow curve showed well single peak at a temperature of 165 ◦C. The effect of Eu3+ concentration at fixed X-ray exposure time was studied and maximum TL occurred at x=0.02. Also the variation of TL intensity with X-ray time (5 to 15 min) showed linear response with dose. The TL glow peak shows more stability and less fading in prepared phosphor which is suitable for TL dosimetry.

Luminescence Studies of Transition Metal (Cu+ and Ag+ Ions) Activated Alkali Zinc Mixed Phosphate

Because of the importance of inorganic phosphates in the solid-state lighting industry, KZnPO4 doped with some transition metal dopant ions like Cu+ and Ag+ ions were prepared by low-cost co-precipitation method at room temperature followed by annealing at a high temperature around 6500C. The prepared phosphors were characterized by X-ray diffraction. In the case of a Photoluminescence study for KZnPO4 doped with Cu+, the emission was observed at 425 nm, which corresponds to the emission of Cu+ ion. In the case of Ag+ doped KZnPO4, weak emission was observed at 420 nm, which is assigned to the emission of Ag+ ions. CIE chromaticity coordinate of KZnPO4 doped with Cu+ and Ag+ ions phosphor was also evaluated via using OSRAM SYLVANIA color calculator and colour purity of concentration was nearly 95% of Cu+ and Ag+ ions. The obtained outcomes revealed that the prepared phosphor shows potential application in the field of solid-state lighting.

A novel red phosphor of Mn4+ion-doped oxyfluoroniobate BaNbOF5for warm WLED applications

A novel red phosphor composed of Mn4+-activated oxyfluoroniobate BaNbOF5was obtained at room temperature in air. The as-prepared phosphor showed a broad and intense absorption in the blue-light region and a bright red luminescence with a color purity of 97.7%.

Shortwave Triboluminescence of Ce Doped Silicate Phosphor in Sliding Friction and its Potential Application as Light Source Means for Controlling Agricultural Pests

The Ce doped Strontium Magnesium silicate phosphor Sr2MgSi2O7:Ce is compounded by using high temperature roasting process, and the plane sample of prepared phosphor is obtained by tablet press method. A modified MCJ-01A friction tester with the friction pair of glass bar against on the plane phosphor sample is used to determine the triboluminescence property of Ce doped Strontium Magnesium silicate phosphor in the linear contact sliding friction. Examination on the triboluminescence of Ce doped Strontium Magnesium silicate phosphor indicates that a quality triboluminescent phosphor with 448nm± blue spectrum emission can be obtained only in the 1200°C calcining temperature, and only 0.010 molar Ce doping concentration in the Sr2MgSi2O7:Cex can promote the prepared phosphor to generate a higher triboluminecent emission and a smaller full width at half maximum (FWHM). The suitable level of applied load is beneficial to hold a balance between wear increment and spectrum intensity. Finally a triboluminescent unit with squirrel cage structure is constructed to realize the triboluminescence of multiple glass bars against on the cylindrical phosphor in the manner of sliding friction. This can satisfy the light emitting of 360o azimuth, and generate more tribological luminous flux.

Luminescence Properties of Rare Earth Activated Aluminates Based Phosphor

A blue emitting phosphor BaAl2O4 doped with Gd3+ were prepared by combustion method at 5000C. The prepared phosphor were investigated by X-ray Diffraction to determine the crystalinity. Photoluminescence emission spectra centred at 369 nm under ultraviolet region, which corresponds to 5d-4f transition of Gd3+ ions. The PL spectra showed strong emission peak intensity and extending to 400nm to 453nm.Concentration quenching mechanism were occurred about 1mol% of Gd3+ ion. The results revealed that phosphor prepared by using combustion method can be useful WLED.

Thermoluminescence Behavior under Different Mega Voltage of Aluminates Based Phosphor

Phosphor material CaYAl3O7 with transition metal Mn2+ were prepared by combustion method at 500°C. The prepared phosphor material characterized for their crystallinity and nature by powder XRD and FTIR. For the thermoluminescecne study, the samples irradiated with 6MeV and 16 MeV. In this voltage phosphor exhibit TL spectra at 1900c that corresponding to dosimetric peak. From the observations and detailed kinetic parameter study shows that phosphor can be act as dosimeter.

The down conversion properties of a Gd2O3:Er3+ phosphor prepared via a combustion synthesis method

Er3+ doped Gd2O3 phosphors were prepared via a combustion synthesis method. The prepared phosphor emits visible green colour.

Structural behavior and Judd–Ofelt intensity parameter of Sr3B2O6:Eu3+ phosphor

In this study, the [Formula: see text] phosphors were synthesized using combustion process and the annealing treatment. Structural behaviors of the prepared phosphor were explored by using X-ray diffraction (XRD), Raman spectra analysis and optical characteristics were studied by excitation and photoluminescence spectra. The phonon sideband (PSB) spectrum associated with [Formula: see text]–[Formula: see text] excitation transition was used to estimate the electron–phonon coupling constant (g) and local structure of the [Formula: see text] ions with its surrounding ligands. Judd–Ofelt (J–O) intensity parameters obtained from emission spectra have been used to evaluate the local site symmetry around [Formula: see text] ions.

Thermoluminescence and Photoluminescence Study of Erbium Doped CaY2O4 Phosphor

Phosphor doped with erbium ion with variable concentration (0.5–2 mol%) was synthesized by solid state reaction method. CaY2O4:Er3+ phosphor is characterized by X-ray diffraction technique for structural analysis and crystallite size calculation. Average crystallite size was found to be nearly 58 nm. Two prominent TL glow peaks found at 163°C associated with higher temperature peak 340°C. The peak intensity of higher temperature (340°C) peak was less as compared to lower temperature peak (163°C) because the deep trapping formation is less in case of UV irradiation. Sample shows good TL glow curve and for variable UV exposure time maximum TL intensity was found at 20 min UV exposure which is optimized UV exposure time. Sample was studied by photoluminescence emission spectra excited by xenon flash lamp with nearly 360 nm and four prominent peaks found at wavelengths 445, 525, 553, and 565 nm; here the 445 and 565 nm peak were intense as compared to others. From the PL emission spectra, it is concluded that the color tenability of prepared CaY2O4:Er3+ was blue-green and it is verified by CIE coordinate. Kinetic parameters of prepared phosphor were calculated by computerized glow curve deconvolution (CGCD) technique.