【作者】 李勃；

【导师】 李龙土； 周济；

【作者基本信息】 清华大学 ， 材料科学与工程， 2004， 博士

【摘要】 具有周期性介质结构的光子晶体(Photonic crystal)亦称光子带隙材料(Photonic bandgap material),是目前信息功能材料研究的前沿领域。本论文以自组装光子晶体为主要研究对象,系统研究了作为光子晶体的二维或三维亚微米周期结构制备方法、微观结构与光学性质。通过电泳方法制备出单层微球六角密排点阵二维有序模板;通过蒸发-表面张力作用制备多层微球面心立方点阵结构蛋白石三维有序模板。分析了微球模板自组装过程的动力学模型。自组装蛋白石模板具有不完全光子带隙,且带隙性质受到模板缺陷的影响。通过对模板进行热处理,可以在较小范围内改变微球点阵的结构参数,从而不可逆的精细调节带隙位置。通过溶胶-凝胶方法制备具有不同填充率的PLZT、TiO2和Zn2SiO4:Mn2+(ZMS) 功能陶瓷基反蛋白石材料,证明溶胶-凝胶方法对于陶瓷基反蛋白石材料制备具有普遍适应性。发现陶瓷基反蛋白石材料中的结晶形态随着烧结温度变化发生明显变化;通过分析反射谱中的Fabry -Perot干涉计算出反蛋白石材料厚度。在国际上首次通过实验发现铁电PLZT反蛋白石材料具有可调光子带隙,带隙中心随外加电场强度增加向长波方向移动,并最终达到饱和。该性质可用于基于光子晶体超棱镜(superprism)效应的新型电控光开关设计。发现Zn2SiO4:Mn2+荧光材料反蛋白石结构中虽然不存在完全光子带隙,但不同晶面对于处于其相应光子带隙中的光发射具有抑制作用,可以阻止沿特定晶面方向的自发辐射。对具有结构反光性质蝴蝶鳞片的微观结构分析证实特殊生物组织体可以构成具有反光作用的二维有序结构。确认了蝴蝶具有三种典型的显色模式:光栅式(光子带隙)反射、回归式反射和色素着色漫散射,提供了区分结构反光与色素反光的实验证据。首次通过溶胶-凝胶方法制备蝴蝶翅膀的二维有序陶瓷基反演结构。更多还原

【Abstract】 Photonic bandgap (PBG) materials (photonic crystals) with regular periodicity of dielectric structures are the frontier of functional materials for their ability in manipulating photons. This dissertation focuses on the sub-micron self-assembled photonic crystals. The preparation methods, microstructures and optical properties of 2-dimensional and 3-dimensional sub-micron periodic structures were studied systematically.2-dimensional template of monolayer microspheres with ordered close-packed hexagonal lattice has been assembled by electric-field-induced deposition process against gravity, and 3-dimensional opal template of multilayer microspheres with face-centered cubic lattice has been assembled by the combined action of evaporation and surface tension respectively. The kinetic model of the microsphere template’s assembly process was analyzed also. Self-assembled opals possess pseudo photonic bandgap, and the bandgap property was influenced by the defects of template drastically. The microsphere lattice’s structural parameters can be changed by annealing polymer opal templates at elevated temperature; it provides the possibility to fine-tune the bandgap properties of photonic crystals irreversibly.PLZT, TiO2 and Zn2SiO4:Mn2+(ZMS) functional ceramic inverse opals with different infilling ratios have been fabricated by sol-gel process. It testifies that sol-gel process is fit for the preparation of different sorts of ceramic matrix inverse opal materials universally. The crystalline forms of ceramic matrix inverse opal materials are changed distinctly with the increase of treating temperature. The thickness of the inverse opal materials has been estimated by analyzing the Fabry-Perot fringe in reflective spectra.It is confirmed that ferroelectric PLZT inverse opal materials possess electrically tunable Photonic bandgap for the first time. The bandgap position <WP=6>shifts continuously to long-wavelength with increasing of the applied electric field. It should supply a more reliable mode to design the novel electric controlled optical switch based on the superprism effect in photonic crystals.Different crystal planes of luminescent Zn2SiO4:Mn2+ inverse opals forbid the light propagation falling in the directional bandgaps though there is no complete bandgap in Zn2SiO4:Mn2+ inverse opals, leading to the inhibition of spontaneous emission in certain directions. The microstructure analysis of the butterfly wing’s squamae with structure color properties shows that the specific bio-tissue is patterned with 2D ordered periodic dielectric changes. Three typical modes for the color display have been summarized as: raster (2-dimensional PBG) reflection, regressive reflection and pigment colored diffusion. The 2D ordered inverse structure of butterfly wing’s squamae formed by ceramic matrix has been fabricated through sol-gel process for the first time.更多还原