학술논문
연소합성법에 의한 디스플레이용 ZnGa2O4계 나노 형광체의 특성 / Characteristics of ZnGa2O4 nano phosphor for display via a combustion method
Document Type
Dissertation/ Thesis
Author
Source
Subject
Language
Korean
Abstract
본 연구에서는 차세대 평판 디스플레이 기술로 주목 받고 있는 FED, VFD에 사용되는 음극선 및 전계 발광용 ZnGa₂O₄ 형광체를 저온공정으로 미립의 입자가 균일하게 얻어지고, 외부의 추가적인 열원이 없이 연료물질과 nitrate 이온의 발열반응만으로 간단하게 형광체의 합성이 가능한 장점을 가지고 있는 연소합성법으로 제조하였고, 녹색과 적색 발광을 위하여 각각 Mn²+, Cr³+ 이온을 ZnGa₂O₄에 첨가 하였다. 합성된 ZnGa₂O₄ 형광체의 특성은 SEM(scanning electron microscope), PL(photoluminescence), XRD(X-ray diffraction)으로 분석하였다.XRD 분석 결과 800℃의 저온에서 ZnGa₂O₄ 결정상이 형성됨을 알 수 있었으며, 소결온도가 상승하면서 결정성이 향상되어 1200℃에서 가장 우수한 결정성을 갖는 ZnGa₂O₄ 상이 형성되었고, 입자의 크기는 약 200nm 내외의 작은 구형 입자를 형성하였다. PL 측정결과 또한, XRD 결과와 동일하게 소결온도 1200℃에서 425nm의 중심피크를 갖는 청색의 형광체로서 가장 우수한 발광특성을 나타내었다. 연료에 따른 특성 비교에서는 결정성, 발광특성 모두 Glycine으로 합성한 ZnGa₂O₄ 형광체가 가장 우수한 결과를 나타내었다. 상기 결과에 의하여 Glycine을 사용한 연소합성법과 1200℃ 소결온도로 Mn²+과 Cr³+의 doping 농도를 변화시키면서 각각의 특성을 알아보았다. Mn²+과 Cr³+ doping시 XRD 측정결과 치환된 Mn²+과 Cr³+ ion에 따른 결정구조상의 변화가 없는 것으로 보아 Zn²+ ion과 치환이 잘 이루어졌으며, PL 측정결과 505nm와 696nm에서 최대 발광 peak를 갖는 녹색 및 적색 형광체로서, Mn=0.004mol, Cr=0.002mol에서 가장 우수한 발광세기를 얻을 수 있었다.
FEDs(field emission displays) have recently gained much attention as they are considered next generation flat panel displays. In this study, ZnGa₂O₄ phosphors in its application to field emission display(FED) and Vacuum Fluorescence Display(VFD) were synthesized by combustion method and Mn²+ ions, a green luminescence activator, and Cr³+ ions, a red luminescence activator were separately doped into ZnGa₂O₄. Using this method, the heating and evaporation of metal nitrate solution with fuel result in self-firing and generates intense heat by exothermic reaction. Due to its high temperature and pressure reaction condition, highly pure nano-sized metal oxide powders could be synthesized. The properties of ZnGa₂O₄ phosphors were investigated by SEM(scanning electron microscope), PL(photoluminescence) and XRD(X-ray diffraction).The X-ray diffraction patterns of ZnGa₂O₄ phosphor showed the position of (311) main peak at the sintering temperature of 800℃. The (311) main peak of ZnGa₂O₄ phosphor is increased under the effect of sintering temperature. The PL spectrums of ZnGa₂O₄ phosphor showed main peak of 425nm, and maximum intensity at the sintering temperature of 1200℃. SEM images shown that nano sized particles(about 200nm) were of spherical shape. Under various fuels(Glycine, Citric acid and Urea), the intensity of blue emission band showed maximum intensity at Glycine. And the characteristics of ZnGa₂O₄ containing 0.004mol Mn²+(505nm, green) and ZnGa₂O₄ containing 0.002mol Cr³+(696nm, red) were shown to be the best.
FEDs(field emission displays) have recently gained much attention as they are considered next generation flat panel displays. In this study, ZnGa₂O₄ phosphors in its application to field emission display(FED) and Vacuum Fluorescence Display(VFD) were synthesized by combustion method and Mn²+ ions, a green luminescence activator, and Cr³+ ions, a red luminescence activator were separately doped into ZnGa₂O₄. Using this method, the heating and evaporation of metal nitrate solution with fuel result in self-firing and generates intense heat by exothermic reaction. Due to its high temperature and pressure reaction condition, highly pure nano-sized metal oxide powders could be synthesized. The properties of ZnGa₂O₄ phosphors were investigated by SEM(scanning electron microscope), PL(photoluminescence) and XRD(X-ray diffraction).The X-ray diffraction patterns of ZnGa₂O₄ phosphor showed the position of (311) main peak at the sintering temperature of 800℃. The (311) main peak of ZnGa₂O₄ phosphor is increased under the effect of sintering temperature. The PL spectrums of ZnGa₂O₄ phosphor showed main peak of 425nm, and maximum intensity at the sintering temperature of 1200℃. SEM images shown that nano sized particles(about 200nm) were of spherical shape. Under various fuels(Glycine, Citric acid and Urea), the intensity of blue emission band showed maximum intensity at Glycine. And the characteristics of ZnGa₂O₄ containing 0.004mol Mn²+(505nm, green) and ZnGa₂O₄ containing 0.002mol Cr³+(696nm, red) were shown to be the best.