【作者】 张平；

【导师】 罗志伟；

【作者基本信息】 中南大学 ， 材料与化工（专业学位）， 2023， 硕士

【摘要】 尖晶石型镓酸锌（ZnGa₂O₄）晶体是一种宽带隙氧化物,其光学带隙在4.4～4.5 e V范围。由于其优异的化学稳定性、阴极发光和光致发光性能,ZnGa₂O₄成为了基于真空荧光、场发射和电致发光的显示器件等领域极具吸引力的候选材料,受到了广泛的关注。本论文以物化性能优异的硅酸盐玻璃为基质材料,通过对Si O₂-Ga₂O₃-Zn O体系玻璃进行受控热处理制备出了含有ZnGa₂O₄纳米晶的透明微晶玻璃,并进一步探讨了ZnGa₂O₄透明微晶玻璃的微观结构和光致发光等性能。主要获得以下研究结果。1、制备了具有不同Ga/Zn摩尔比的Si O₂-Ga₂O₃-Zn O体系基础玻璃,并采用“一步法”热处理工艺,制备出了具有不同Ga/Zn比和不同热处理制度的ZnGa₂O₄透明微晶玻璃。研究了该体系玻璃的析晶动力学,以及微晶玻璃的微观结构,物理性能以及发光性能。结果表明,随着Ga/Zn比的增长,ZnGa₂O₄微晶玻璃基体内的析晶模式由整体析晶向表面析晶转变,基体中ZnGa₂O₄晶粒的尺寸从～87 nm减小到了～6 nm。制备的ZnGa₂O₄微晶玻璃可以在350-650 nm以及670-800 nm范围内产生发光,而且随着Ga/Zn比的变化,其发射峰的形状发生了明显的偏移。随着热处理温度的增加,ZnGa₂O₄微晶玻璃的结晶度以及发光强度均呈现出上升的趋势。确定了该体系ZnGa₂O₄透明微晶玻璃的最佳Ga/Zn摩尔比为4.00,最佳热处理制度为900℃/4 h。2、成功制备了Er³⁺-Cr³⁺单掺/共掺ZnGa₂O₄透明微晶玻璃。研究结果表明,Er³⁺离子会在ZnGa₂O₄晶体周围富集,促进ZnGa₂O₄晶体的生长,其平均晶粒尺寸为15 nm。而Cr³⁺离子成功占据ZnGa₂O₄晶格中八面体位点(Ga³⁺位点),但是会抑制ZnGa₂O₄晶体的生长,其平均晶粒尺寸为6 nm。热处理前后,Cr³⁺离子所处的配位场场强从2.17增加至2.86,导致其发射光谱的峰位从850 nm移至688 nm。在378 nm氙灯光源激发下,Er³⁺/Cr³⁺共掺杂基础玻璃只展现出Er³⁺特征发射峰,但其微晶玻璃的发射峰中同时存在Er³⁺和Cr³⁺离子的特征发射峰,在980 nm激发下,Er³⁺/Cr³⁺共掺杂基础玻璃热处理前后的发射光谱只存在Er³⁺离子特征发射峰。结果表明该体系ZnGa₂O₄透明微晶玻璃是一种良好的过渡金属离子掺杂基质发光材料。3、成功制备了Mn²⁺离子单掺和Mn²⁺/Cr³⁺离子共掺ZnGa₂O₄透明微晶玻璃。研究了Mn²⁺离子在六配位和四配位环境下的可见光发光性能,以及Mn²⁺、Cr³⁺离子同处于ZnGa₂O₄微晶玻璃中的可见光发光性能。结果表明,基础玻璃中,Mn²⁺离子主要以六配位的形式占据网络形成体,该发光中心可以发射出峰值为～600 nm的橙光;在ZnGa₂O₄微晶玻璃中,Mn²⁺离子和Cr³⁺离子分别占据ZnGa₂O₄尖晶石中的四面体位点(Zn²⁺位点)和八面体位点(Ga³⁺位点),分别发射出峰值位于～510 nm和～688 nm的绿光和红光。存在Mn²⁺→Cr³⁺的能量转移机制,通过改变Mn²⁺/Cr³⁺摩尔比以及测试条件,可以产生不同颜色的发光。CIE结果表明,Mn²⁺离子单掺杂基础玻璃和微晶玻璃可以应用于橙黄、绿光显示器,而Mn²⁺/Cr³⁺离子共掺杂ZnGa₂O₄微晶玻璃可以作为绿、红光显示器的理想材料。图51幅,表16个,参考文献148篇更多还原

【Abstract】 The spinel type zinc galliate（ZnGa₂O₄）crystal is a wide-band compound with optical band-gap in the range of 4.4～4.5 e V.Due to its good chemical stability,cathodoluminescence,and photoluminescence properties,ZnGa₂O₄ has become a particularly attractive candidate material for display devices based on vacuum fluorescence,field emission,and electroluminescence,and has received wide attention.In this work,transparent glass-ceramics containing ZnGa₂O₄ nanocrystals were prepared by using silicate glass with excellent physical and chemical properties as matrix material,and the crystallization kinetics,microstructure,and photoluminescence properties of ZnGa₂O₄ transparent glass-ceramics were further analyzed.The following research results were obtained.1.Si O₂-Ga₂O₃-ZnO system parent glasses with different Ga/Zn molar ratios were prepared,and ZnGa₂O₄ transparent glass-ceramics with different Ga/Zn ratios and different heat treatment systems were prepared by using the"one-step"heat treatment process.The crystallization kinetics of the parent glasses in this system,as well as the microstructure,physical properties,and luminescent properties of the glass-ceramics were studied.The research results show that with the increase of Ga/Zn molar ratio,the crystallization mode of glass-ceramics changes from overall crystallization to surface crystallization,and the size of ZnGa₂O₄ grains in the glass matrix decreased from～87 nm to～6 nm.The prepared ZnGa₂O₄ glass-ceramics can produce fluorescence emission in the range of 350-650 nm and 670-800 nm,and the emission peak shapes change obviously with the rise of Ga/Zn ratio.In addition,with the increase of heat treatment temperature,the crystallinity and fluorescence properties of ZnGa₂O₄glass-ceramics show an upward trend.Finally,the optimum Ga/Zn molar ratio of the ZnGa₂O₄ transparent glass-ceramics in this system was determined as 4.00,and the optimum heat treatment system was determined as 900℃/4 h.2.Er³⁺-Cr³⁺single-doped/co-doped ZnGa₂O₄ transparent glass-ceramics have been successfully prepared.Er³⁺-Cr³⁺ions doped ZnGa₂O₄transparent glass-ceramics were successfully obtained by"one-step"heat treatment process.The research results show that Er³⁺ions can enrich around ZnGa₂O₄ crystal and promote the growth of ZnGa₂O₄ crystal,with an average grain size of～15 nm.And,Cr³⁺ions can successfully occupy the octahedral site in ZnGa₂O₄ lattice,but will inhibit the growth of ZnGa₂O₄ crystal,with an average grain size of～6 nm.Before and after the heat treatment,the coordination field intensity of Cr³⁺ions increased from2.17 to 2.86,resulting in the peak position of its emission spectrum from850 nm to 688 nm.Under the excitation of 378 nm Xenon lamp,the Er³⁺/Cr³⁺co-doped parent glass only showed the characteristic emission peak of Er³⁺ions.However,there were characteristic emission peaks of Er³⁺and Cr³⁺ions in the emission peaks of its glass-ceramics.Under the excitation of 980 nm,the emission spectrum of Er³⁺/Cr³⁺co-doped glasses before and after the heat treatment only showed the characteristic emission peak of Er³⁺ions.The results show that the ZnGa₂O₄ transparent glass-ceramics in this system are good transition metal ion-doped matrix material.3.Mn²⁺ions single-doped and Mn²⁺/Cr³⁺ion co-doped ZnGa₂O₄transparent glass-ceramics were successfully prepared.The visible fluorescence properties of Mn²⁺ions in six and four coordination environments and the visible fluorescence properties of Mn²⁺/Cr³⁺ions co-doped ZnGa₂O₄ glass-ceramics were studied.The results show that in the parent glass,Mn²⁺ions mainly occupy the network forming body in the form of six coordination,and the luminous center can emit orange light with a peak of～600 nm;in ZnGa₂O₄ glass-ceramics,Mn²⁺ions and Cr³⁺ions occupy tetrahedral sites(Zn²⁺sites)and octahedral sites(Ga³⁺sites)in ZnGa₂O₄ spinels,respectively,emitting green and red light with peaks at～510 nm and～688 nm,respectively.There is an energy transfer mechanism of Mn²⁺→Cr³⁺.Different colors of luminescence can be produced by changing the molar ratio of Mn²⁺/Cr³⁺and test conditions.The CIE results show that Mn²⁺ions single-doped parent glass and glass-ceramics can be used in orange and green light displays,while Mn²⁺/Cr³⁺ion co-doped ZnGa₂O₄ glass-ceramics can be used as ideal materials for green and red light displays.Figures 51,Tables 16,Reference 148更多还原