碳纳米管场发射荧光管的制备及性能研究

【作者】 袁红梅；

【导师】 林祖伦；

【作者基本信息】 电子科技大学 ， 光学工程， 2010， 硕士

【摘要】 场发射光源具有低功耗、高亮度、长寿命、无污染等优点,近年来成为人们研究的热点。本文围绕碳纳米管场发射荧光管的实用化研究,针对其阳极荧光屏的制作,开展了阳极ITO透明导电层的研制、荧光粉层的涂敷工艺研究及荧光管的组装与测试三部分工作。首先,本文重点研究了ITO薄膜的溶胶—凝胶制备工艺。以硝酸铟、氯化锡、乙酰丙酮为原料配制溶胶,用提拉法在普通玻璃基底与玻璃管内壁上拉制湿膜,最后进行烧结热处理制备ITO薄膜。研究了铟离子浓度、掺锡摩尔比、热处理温度、热处理时间、镀膜次数等相关制备工艺参数对ITO薄膜结构、形貌及光电性能的影响,结论如下:(1)XRD分析结果表明Sn元素被有效的掺进了氧化铟晶格中,ITO薄膜具有立方铁锰矿结构,并呈[111]方向择优生长。(2)SEM分析结果表明ITO薄膜表面呈纳米粒子堆积而成的多孔结构。(3)ITO薄膜的方阻随溶胶中In 3+浓度的增加而降低,当In 3+浓度增加到一定值后,薄膜表面均匀性降低,薄膜方阻变化较小,在In3+浓度为0.2 mol/L时,薄膜的导电性与均匀性最好。(4)ITO薄膜的方阻随掺锡比的增加而降低,掺锡比大于5%后薄膜方阻变化缓慢,在掺锡比为15%时方阻最小;ITO薄膜的可见光平均透过率随掺锡比的增大而增大。(5)ITO薄膜的方阻随热处理温度、热处理时间及膜厚的增加而降低,分别在450℃及8 h时薄膜的方阻最小;ITO薄膜的可见光平均透过率随热处理温度的增加而增大,随膜厚的增加而减小。(6)采用最佳工艺参数制备了具有良好光电性能的场发射荧光管阳极ITO导电层,其中ITO薄膜的方阻为360Ω/□,可见光平均透过率约为82%。其次,采用电泳法涂覆荧光粉层,研究了相关制备工艺参数(包括荧光粉浓度、电解质浓度、电泳电压、电泳时间)对沉积荧光粉层厚度与表面形貌的影响,确定了制备荧光粉层的最佳工艺参数为:荧光粉浓度10 g/L、电解质浓度0.128 g/L,电泳电压100 V,电泳时间2 min,获得了表面均匀、厚度理想的阳极荧光层。最后,组装碳纳米管场发射荧光管,并在真空环境下进行动态点亮测试。结果表明,碳纳米管场发射荧光管可以瞬间点亮、连续调光,当阳极电压为5 kV时,发光亮度为3519 cd /m2。更多还原

【Abstract】 Field emission light source has drawn wide attention for its low power consumption, high brightness, long working-life and non-pollution. This paper focused on the practical research of carbon nanotube field emission fluorescent devices and the fabrication of anode fluorescent screen, carrying out the fabrication of ITO film anode, the coating of phosphor layer, as well as the assembling and testing of fluorescent tube.Firstly, ITO conductive anode films were fabricated on glass tube substrates by sol-gel process. The sol was prepared using indium nitrate, stannic chloride and acetylacetone. Then, the wet-films were prepared on glass substrates by dip-coating method. In the end, the ITO films were obtained after sintering process. The effect of various process parameters, including In3+ concentration, Sn-doped proportion, sintering temperature and time, as well as layer number of the film, on the structure, surface morphology and opt-electric properties of ITO films were studied and discussed. Certain conclusions were obtained as follow:(1) XRD results suggested that Sn was effectively doped into the lattice of indium oxide, and the ITO film has the Polyerystalline eubicbixbyitel In2O3 structure.(2) SEM results indicated that the surface of ITO films presented a porous structure accumulated by nano-particles.(3) The sheet resistance of ITO films decreased as the increase of In3+concentration in the sol. When In3+ concentration increased to a certain level, the uniformity of the thin film reduced, while the sheet resistance changed slightly. When In3+ concentration was 0.2 mol/L, the sheet resistance and the uniformity of the film reached to the best level.(4) The sheet resistance of ITO films decreased as the increase of the Sn-doped proportion. The sheet resistance changed slowly when Sn-doped proportion was higher than 5%, and It achieved the minimum when Sn doping ratio was 15%. The average visible transmittance of ITO films increased when the Sn-doped proportion increased.(5) The sheet resistance of ITO films decreased as the increase of sintering temperature and time, as well as film thickness. When the sample was sintering at 450℃for 8h, its sheet resistance reached the minimum value. The average visible transmittance of ITO films increased with the augment of sintering temperature and decreased with the increase of film thickness.(6) An anode ITO conductive layer of field emission fluorescent tube with excellent opt-electric performances was obtained in the end. The sheet resistance of the ITO film prepared by the same processing condition was 360Ω/□, and the average visible transmittance was about 82%.In addition, phosphor layers were fabricated by electrophoretic deposition. The effect of various process parameters, including phosphor concentration, electrolyte concentration, electrophoretic voltage and electrophoretic time, on the thickness and surface morphology of phosphor layers were analyzed. The best process parameters were obtained: the phosphor concentration was 10 g/L, the electrolyte concentration was 0.128 g/L, electrophoretic voltage was 150 V while the electrophoretic time was 2 min. An anode fluorescent tube with homogeneous surface and ideal thickness was fabricated at last.In the end, the carbon nanotube field emission fluorescent tube was assembled, lightened and tested in vacuum atmosphere. The results showed that carbon nanotube field emission fluorescent tube could be lightened instantly, and the light could be continuously modulated as well. When the anode voltage was 5kV, the brightness was 3519 cd/m2.更多还原