CAREER: Nonspherical, Active, and "Inverted" Bases for Optimized Photonic Crystal Design

技术本项目专注于合成和表征具有定制的形貌和组成的无机胶体，以更好地理解和制造三维光子晶体结构。通过研究以非球形和活性胶体为基团的光子晶体，将探索新的构型和功能。工作在近红外和可见光区域的光子带隙材料(光子晶体)的实现依赖于单分散或均匀尺寸的纳米和介观粒子的有序晶格。这克服了传统胶体构建块的局限性，如二氧化硅(SiO_2)和聚苯乙烯球，它们具有较差的光学功能(低折射率)，并且无法产生必要的多样化堆积排列，以实现光子晶体预期的最有希望的光学性能增强。具有功能性的单分散胶体(金属、半导体、磁性陶瓷等)它们有望用于各种电光应用，但尚未得到广泛应用。在拟议的研究中，将研究扩大胶体组成和形态控制的技术，以制备包括非球形、核壳、中空和发光粒子在内的高折射率单分散胶体。除了自组装策略外，还将利用光刻制作的场和模板来组织粒子。对组件光学属性进行建模将能够改进几种类型的非球形构件的光子晶体设计要求。研究方法还包括使用表征技术来成像组件内的电磁模式。因此，理论上的光子能带计算将与新型光子晶体材料的结构和性质直接相关。人们希望更好地理解调整单粒子属性(包括对称性降低)对光子带特性的影响。了解材料的拓扑结构和功能之间的关系将有助于实现新的功能性光子晶体结构。研究将与教育和外展工作紧密结合。拟议开展一项外联活动，通过挑战“游戏”和将艺术与技术相结合的认知活动，在大学前一级培养对材料科学和工程的欣赏能力。这款面向中学生的拼图游戏将扫描电子显微镜艺术作为理工科教育的一种工具。PI还计划将她目前在细颗粒技术和自组装方面的研究想法和方法融入到一个新的互动课程中，该课程将加强研究生和本科生材料科学和工程教育之间的联系。这种方法是新颖的，其评估具有将科学研究提升到工程教育中的潜力。此外，还计划开展活动，鼓励就读于历史上黑人学院和大学的女本科生从事纳米和中尺度系统的暑期研究体验。这有可能加强康奈尔大学材料科学与工程系与少数族裔服务机构的物理科学和工程系(以及教员)之间的网络关系。预计这也将导致少数族裔女性研究生院的申请者和入学人数增加。

TechnicalThis project focuses on synthesis and characterization of inorganic colloids with tailoredmorphology and composition for greater understanding and fabrication of three-dimensional photonic crystal structures. New configurations and functionality will be explored through research on photonic crystals with nonspherical and active colloids as bases. Realization of photonic band gap materials (photonic crystals) operating in the near infrared and visible regions relies on ordered lattices of monodispersed, or uniform sized, nano- and mesoscale particles. This overcomes limitations of traditional colloidal building blocks such as silica (SiO2) and polystyrene spheres, which have poor optical function (low refractive index) and cannot produce the diverse packing arrangements necessary to fulfill the most promising enhancements in optical properties expected from photonic crystals. Monodispersed colloids with functionality (metals, semiconductors, magnetic ceramics, etc.) are promising for a variety of electrooptic applications, but have not been widely available. In the proposed research, techniques to expand colloid composition and morphology control will be studied to produce high refractive index monodispersed colloids including non-spherical, core-shell,hollow, and luminescent particles. Fields and templates made by lithography will be utilized in addition to self-assembly strategies to organize the particles. Modeling the assembly optical properties will enable refinement of the photonic crystal design requirements for several types of non-spherical building blocks. The research approach also includes the use of characterization techniques to image electromagnetic modes within the assemblies. Thus, theoretical photonic band calculations will be directly correlated with the structure and properties of the new photonic crystal materials. Better understanding of the effect of tailoring single particle properties (including symmetry reduction) on photonic band characteristics is sought and anticipated. Understanding of the relationship between material topology and function will aid in achieving new functional photonic crystal structuresNon-TechnicalBroader Impact. Research will be closely integrated with education and outreach efforts. An outreach activity is proposed to build an appreciation for materials science and engineering at the pre-collegiate level through challenging "play" and cognitive activities that integrate art and technology. The jigsaw puzzle outreach to middle school students uses scanning electron microscopy art as a tool in science and engineering education. The PI also plans to incorporate her current research ideas and methods in fine particle technology and self-assembly into a new interactive course offering which will strengthen the linkage between graduate and undergraduate materials science and engineering education. The approach is novel and its evaluation has potential to enhance science studies research into engineering education. In addition, activities are planned that encourage female undergraduates attending Historically Black Colleges and Universities to engage in summer research experiences in nano- and mesoscale systems. This has the potential to strengthen network relationships between the Cornell University Department of Materials Science and Engineering and the physical science and engineering departments (and faculty) at minority serving institutions. It is also expected to lead to increased minority female graduate school applicants and admissions.