| Summary: | 碩士 === 國立臺北科技大學 === 材料科學與工程研究所 === 99 === This study is focused on the synthesis and luminescent properties of novel alkaline silicate phosphors. Conventional solid state reaction method is adopted to synthesize earth element-activated phosphors and co-doping phosphors. To synthesize Ba3MgSi2O8 host, we discuss the effect of different flux, flux concentration, firing temperture.In doping process the effect of different firing temperture, doping concentration and atmosphere on the luminescent properties is observed.Finally we try to make a EL device with Ba3MgSi2O8 phosphor we made.
When we add 2wt% of H3BO3 and fireing temperture 1250°C, we will have Ba3MgSi2O8 with good emission property.The emission peaks of Ba3MgSi2O8:Eu3+ phosphor is originated from 5D0→7FJ(J=1,2,3,4) transitions, which show a orange-red color and are also independent of host lattice surroundings. And Ba3MgSi2O8:Eu2+phosphors show a 4f65d→8S7/2 transition with blue 442nm emission, which depends on the covalence and crystal field splitting effects of the host lattice.Due to sensitizer, Ba3MgSi2O8:Eu2+,Dy3+ have better emission intensity and long afterglow property. Ba3MgSi2O8:Eu2+,Mn2+ will show white color and show different color with different doping concentration.
The EL device show emission intensity and we can use it in special situation.Based on excitation spectra analysis and UV-vis analysis ,the main excitation peaks of Ba3MgSi2O8:Eu3+ ,Ba3MgSi2O8:Eu2+ , Ba3MgSi2O8:Eu2+,Dy3+ and Ba3MgSi2O8:Eu2+,Mn2+ phosphors are located at ultraviolet region of the spectrum. Due to its high emission intensity, these phosphors possess potentials on UV-chip excited WLED applications.
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