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

技术：该项目专注于无机胶体的合成和表征，具有定制的形态和组成，以更好地理解和制造三维光子晶体结构。通过以非球形和活性胶体为基础的光子晶体的研究，将探索新的结构和功能。光子带隙材料（光子晶体）在近红外和可见光区域的实现依赖于单分散的有序晶格，或均匀尺寸的纳米和中尺度粒子。这克服了传统胶体构建块（如二氧化硅（SiO2）和聚苯乙烯球）的局限性，这些胶体构建块具有较差的光学功能（低折射率），并且不能产生满足光子晶体光学性能最有希望的增强所必需的各种包装排列。具有功能性的单分散胶体（金属、半导体、磁性陶瓷等）在各种电光应用中很有前景，但尚未得到广泛应用。在提出的研究中，将研究扩大胶体组成和形态控制的技术，以生产高折射率单分散胶体，包括非球形、核壳、空心和发光颗粒。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。对组装光学特性进行建模将使改进几种非球形构建块的光子晶体设计要求成为可能。研究方法还包括使用表征技术对组件内的电磁模式进行成像。因此，理论光子带的计算将与新型光子晶体材料的结构和性质直接相关。更好地理解裁剪单粒子性质（包括对称减少）对光子带特性的影响是寻求和期望的。理解材料拓扑和功能之间的关系将有助于实现新的功能光子晶体结构。研究将与教育和外联工作密切结合。通过具有挑战性的“游戏”和整合艺术和技术的认知活动，提出了一项拓展活动，以建立对大学前水平的材料科学和工程的欣赏。这个面向中学生的拼图游戏将扫描电子显微镜艺术作为科学和工程教育的工具。她还计划将她目前在细颗粒技术和自组装方面的研究思路和方法融入到一个新的互动课程中，这将加强研究生和本科生材料科学与工程教育的联系。该方法新颖，对工程教育的评价有促进科学研究的潜力。此外，计划开展活动，鼓励在传统黑人学院和大学就读的女本科生参与纳米和中尺度系统的夏季研究经验。这有可能加强康奈尔大学材料科学与工程系与少数民族服务机构的物理科学与工程系（和教员）之间的网络关系。少数族裔女性研究生院的报考人数和录取人数也将有所增加。

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.