Synthesis, Composition Optimization, and VUV Photoluminescence Characterization of (Y,Gd)(V,P)O_4∶Eu^(3+) as A Potential Red-Emitting Plasma-Display Panel Phosphor

The synthesis, composition optimization, VUV Photoluminescence (PL) spectra, and optical properties, of (Y,Gd)(V,P)O4∶Eu3+ phosphors were investigated by synchrotron radiation. The VUV PLE spectra and the correlation among VUV PL intensity, λem, and Eu3+, Gd3+, and P-content were established. The PLE spectral studies showed that (Y,Gd)(V,P)O4∶Eu3+ exhibited significant absorption in the VUV range. The VUV PL intensity was found to enhance with PO43- and Gd3+-doping. Furthermore, the chromaticity characteristics of (Y,Gd)(V,P)O4∶Eu3+ were also found to be (0.6614, 0.3286) and compared against (Y, Gd)BO3∶Eu3+ as a reference. Based on the characterization results, we are currently improving and evaluating the potential application of (Y,Gd)(V,P)O4∶Eu3+ as a new red-emitting PDP phosphor.

Vacuum Ultraviolet Spectral Investigations on Green-Emitting Ca(La,Gd)_4Si_3O_(13):Tb^(3+) Phosphors for PDP Applications

In an effort to develop new green-emitting PDP phosphors with high efficiency, investigated were the synthesis, VUV photoluminescence (PL) spectra, optical properties, and chromaticity of Ca(La1-x-yTbxGdy. )4Si3O13 phosphors by using synchrotron radiation. Upon analysis of the VUV spectroscopic and chromaticity investigations on the new greenemitting VUV phosphors, were an optimized composition achieved. The PLE spectral studies show that Ca ( La1-x-y TbxGdy)4Si3O13 exhibit significant absorption in the VUV range. The VUV PL intensity was found to enhance with Gd3+-doping. Furthermore, the 1931 CIE chromaticity coordinates of Ca(La,Gd)4Si3O13:Tb were found to be (0.286, 0.548), as compared to (0.230, 0.712) for Zn2SiP4:Mn2+ as a reference. The potential application of Ca(La,Gd)4Si3O13:Tb as a new green-emitting PDP phosphor are being currently improving and evaluating.

Effect of Different Conditions on the Structural Color of Konjac Glucomannan Particles

In this paper,molecular dynamics simulation was applied to synthesize a layered structural color from Konjac glucomannan（KGM） and the effect of particle diameter and temperature were investigated. A series of methods such as high voltage electric field treatment,the transfer matrix method and the CIE standard colorimetric system were simulated to obtain the chromaticity coordinates and to analyze the color changes of KGM particles. The results revealed that as the particle diameter increases,the structural color of KGM particles deflects towards the yellow wavelength within the visible spectrum; and as the reaction temperature rises,the structural color deflects towards the blue and violet wavelengths within the visible spectrum.

Synthesis and luminescence properties of KCaPO_4:Eu^(2+),Tb^(3+),Mn^(2+) for white-light-emitting diodes(WLED)

In order to obtain a single-host white-light phosphor, a series of KCaPO4 powder samples tri-doped with Eu2＋, Tb3＋ and Mn2＋ were synthesized via high-temperature solid-state reaction method. Their structural and luminescence properties were investigated. Under proper ultraviolet excitation （255-405 urn）, white light was obtained, consisting of blue, green and red emissions stemming from Eu2＋, Th3＋, Mn2＋ ions respectively. The temperature stability of our sample was analyzed by studying the variation tendeney of CIE chromaticity coordinates at different temperatures. The results indicated that this phosphor could yield good color stability when utilized in WLED.

A novel fluorescent sensor for Al^(3+)and Zn^(2+)based on a new europium complex with a 1,10-phenanthroline ligand

A new europium complex Eu(tta)_(3)Li(la)based on 1,10-phenanthroline derivative(Li=(2-(3,5-dimethoxyphenyl)-1 H-imidazo[4,5-f][1,10]phenanthroline),tta=2-thenoyItrifluoroacetone)was designed and synthesized.Its structure was characterized by^(1)H and^(13)C NMR,elemental analysis,UV-vis,fluorescence spectra and single crystal X-ray diffraction.The crystal of the complex la belongs to monoclinic system with the space group P2_(1/n).The europium complex la in the solid and in the solution displays the typical emission of Eu(III)ion centered at 612 nm as a result of the electric dipole transition(^(5)D_(0)-►^(7)F_(2)).It exhibits high quantum yield(20.42%),long lifetime(0.29 ms)and good CIE color coordinate(0.67,0.33)in solid.In addition,the complex shows high sensitivity and selectivity towards Al^(3+)and Zn^(2+)in methanol solution which can be attributed to the Al^(3+)/Zn^(2+)cation instead of Eu^(3+)in the complex la.The LODs for Al^(3+)and Zn^(2+)were calculated to be 5.880×10^(-7)and 7.678×10^(-8)mol/L,respectively.Besides,the additions of Al^(3+)and Zn^(2+)express remarkable color changes from red to bright blue and ivory that can be clearly observed by the naked eye respectively.

A RGB LED Driving Structure and Signal Processing Based on Tone-to-Color Conversion

In order to solve the uncertainty of voice-to-color conversion in which one of the three voice features（loudness, tone, rhythm） is applied to control LED color, a linear conversion solution is proposed. And a chromaticity diagram is defined by using hue definition on hue-saturation-lightness（HSL） hue ring and the normalization of CIE xyY which is a color standard defined by International Commission on Illumination（CIE）. The chromaticity diagram shows a linear relation between pitch and color, which is referred to conversions of other physical parameters as well. Based on the solution, red（R）, green（G） and blue（B） LEDs, the driving structure of a conversion circuit is designed and set up. The results indicate that signal processing of tone-to-color conversion is effective, from 30 Hz to 3 kHz with a resolution of 10 Hz mapped to the chromaticity diagram.