Patterning Mesoscale Chirality by Guided Crystal Twisting

通过引导晶体扭曲形成中尺度手性图案

• 批准号: 2325911
• 负责人: Stephanie Lee
• 金额: $ 52.45万
• 依托单位: New York University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-03-01 至 2027-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2325911&HistoricalAwards=false
• 关键词: Patterning; Mesoscale; Chirality; Guided; Crystal

Silicon-based semiconductor crystals for computer chips and solar panels epitomize our reliance on crystalline materials and underscore their centrality for information technologies and renewable energies. While defect-free single crystals are the gold standard for most applications, bundles of imperfect, interacting crystals can be superior in some cases. This grant supports research on how organic semiconductor crystals can be fabricated as networks of twisted braids that counterintuitively outperform single crystals in the transport of electrons and detection and emission of different types of light. These twisted crystals are formed from the melt, making it possible to leverage high throughput fabrication methods. These novel materials support plastic electronics industries based on flexible light emitting diodes and displays, transistors, and wearable electronics for sensing and health monitoring thus augmenting the U.S. economy. At the intersection of solid-state physics, materials science, and process engineering, this multidisciplinary research serves as a rich training platform for undergraduate and graduate students, contributing to workforce development as called for by the CHIPS and Science Act. The colorful patterns created by twisted crystals form the basis of interactive STEAM workshops at the K-12 level. Through this activity, students learn about the concepts of crystals and light-matter interactions.Designing materials for chiroptoelectronics has relied on the synthesis of chiral molecules enantioselectively or the labor- and atom-intensive resolution of racemic mixtures of enantiomers. Twisted crystals that form spontaneously from the melt can manifest mesoscale chiroptical properties. The challenges facing the advancement of twisted crystals for chiroptoelectronics are the lack of spatial control over the twist sense and direction, and the incompatibility of current batch processing with high throughput manufacturing. This research articulates mechanisms governing twisted crystal formation and how the organization of crystal fibers affects electron and photon transport. This understanding guides the development of scalable processing methods to fabricate twisted crystal films with prescribed orientations and twist sense. Hybrid screw extrusion and roll-to-roll coating of molten material into patterned films are investigated as a scalable manufacturing method for these chiroptoelectronic materials. This continuous processing method involves inline mixing of molecular compounds and twisting additives prior to extrusion; precise control over film thickness, crystallization temperature, and shear profile; and tunable patterning using corrugated rollers. Newly developed rapid differential polarization imaging for inline characterization during film coating permits the screening and optimization of hundreds of electro-optical thin films made of collimated twisted crystal films. Examples of the applications of twisted crystals are circularly polarized light detectors and waveguides.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

用于计算机芯片和太阳能电池板的硅基半导体晶体体现了我们对晶体材料的依赖，并强调了它们在信息技术和可再生能源中的中心地位。虽然无缺陷的单晶是大多数应用的黄金标准，但在某些情况下，不完美的相互作用的晶体束可能更优越。这笔赠款支持研究如何将有机半导体晶体制造为扭曲辫子网络，使其在电子传输以及不同类型光的检测和发射方面优于单晶。这些扭曲的晶体是由熔体形成的，使得利用高通量制造方法成为可能。这些新型材料支持基于柔性发光二极管和显示器、晶体管以及用于传感和健康监测的可穿戴电子产品的塑料电子行业，从而增强美国经济。这项多学科研究处于固态物理学、材料科学和过程工程的交叉点，为本科生和研究生提供了丰富的培训平台，为《CHIPS》和《科学法案》所要求的劳动力发展做出了贡献。扭曲水晶创造的彩色图案构成了 K-12 级别互动 STEAM 研讨会的基础。通过这项活动，学生了解晶体和光与物质相互作用的概念。手性光电子学材料的设计依赖于对映选择性的手性分子合成或对映体外消旋混合物的劳动和原子密集型拆分。从熔体中自发形成的扭曲晶体可以表现出介观手性光学特性。用于手性光电子学的扭曲晶体的发展面临的挑战是缺乏对扭曲方向和方向的空间控制，以及当前批量处理与高吞吐量制造的不兼容。这项研究阐明了控制扭曲晶体形成的机制以及晶体纤维的组织如何影响电子和光子传输。这种理解指导了可扩展加工方法的开发，以制造具有指定方向和扭曲感的扭曲晶体薄膜。研究了混合螺杆挤出和将熔融材料卷对卷涂覆成图案薄膜作为这些手电光电子材料的可扩展制造方法。这种连续加工方法涉及在挤出之前在线混合分子化合物和加捻添加剂；精确控制薄膜厚度、结晶温度和剪切曲线；以及使用瓦楞辊的可调图案。新开发的快速差分偏振成像用于薄膜镀膜过程中的在线表征，可以筛选和优化数百个由准直扭曲晶体薄膜制成的电光薄膜。扭曲晶体的应用示例是圆偏振光探测器和波导。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。