| Transportation is basic necessity and prerequisite for economic development of a country; it is also an important tool for optimizing the resources allocation and dealing with macroeconomic control. With the sustained development of the transportation industry, new and higher requirements are presented for vehicle materials. New lighting, display and laser materials are widely used in all kinds of vehicles and play important roles. W-LEDs are the fourth generation lighting sources, whose performances have surpassed the high-pressure gas discharge lamps, incandescent and fluorescent lamps. They have been employing in many fields including trains, boats, airplanes lighting, indicators, traffic signal lights and information displays, etc.This dissertation aims at these drawbacks exposed in the present mainstream W-LEDs, for example, light attenuation, easy aging of packaging materials and so on, trys to explore noble metals and rare earth ions co-doped glass materials replacing the commercial phosphors and packaging materials. The possibilities of applying the glass phosphors on W-LEDs and laser materials are also discussed. The achieved main results from the studies on the syntheses and spectral measurements are as follows:(1) A set of borate glasses with compositions40RO-59.5B2O3-0.5Eu2O3(R=Ca, Sr, Ba, Zn or Pb) are designed, and these electron-phonon coupling constants between luminescence center and matrix are calculated. The EPC (electron-phonon coupling constant) values of different samples are very close, approximately equal to0.012. This suggests that the designed glass system is weak electron-phonon coupling system, and the change of RO does not cause significant variation of electron-phonon coupling nature of Eu3+in the slightly different matrix. The Judd-Ofelt theory is used to calculate the optical transition properties of Eu3+in the borate glasses, and the optical transition strength parameters of different samples are obtained. Ω2value of each sample is greater than Ω4and Ω6values. Compared to the other samples, the sample containing PbO component exhibits the minimum Ω2value, but forΩλ values, ZBE, CBE, BBE and SBE are very similar. (2) Eu3+doped borate glasses containing sliver are designed and prepared. The colorimetric properties of69B2O3-30AgNO3-1Eu2O3sample are analyzed and calculated. Changing the excitation wavelength, the color temperature, color coordinates and color rendering index can be adjusted. When λex=330nm, the color temperature is6500K, x, y chromaticity coordinates is (0.312,0.336) and color rendering index is88. Through appropriate design of glass composition, the glass samples containing Ag NPs (nanoparticles) and Ag aggregates can be successfully prepared only by one step melt quenching technique. Monitoring5Doâ†'7F2emission of Eu3+, the energy transfer from Ag aggregates to Eu3+can be observed in the excitation spectra. By adjusting the contents of the Ag and RE ions, the fluorescent material meeting the requirements of color temperature, color coordinates and color rendering index can be prepared.(3) The Sm3+doped borate glasses containing sliver are designed and prepared. In the excitation and emission spectra, the shift of the excitation and emission peaks with excitation and monitoring wavelengths can be observed, which indicates the presence of different luminescence centers (different Ag aggregates states). The color coordinates of these samples fall into yellow region. These results imply that prepared glasses can be used as phosphors for W-LEDs by combining NUV and blue chips (e.g.405and460nm). The designed glass material30CaO-60B2O3-10AgNO3-10Sm2O3has largely wide emission band in the visible range and these gain values are large in the full emission range. This material is a potential diode pumped solid-state laser gain medium for frequency tunable lasers. |
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