Solution-Processed Monodisperse Nanoelectronic Heterostructures

非技术描述：随着便携式和可穿戴电子技术的日益重要，需要将最高的电子性能与其他要求相结合的新材料，如机械灵活性、低功耗和可扩展制造。新兴的原子薄的二维纳米电子材料满足了这些要求中的许多，但没有一种材料可以同时实现所有这些要求。因此，该项目开发了异质结构，协同整合了多种二维纳米电子材料的理想特性，从而克服了单独使用单一材料带来的设计权衡。进一步采用溶液处理方法，以与大规模、低成本的添加剂制造兼容的方式实现高度均一的纳米电子异质结构。该项目的成果通过一套全面的教育和推广活动来传播，这些活动包括研究生课程开发、本科实验室和芝加哥科学与工业博物馆的材料科学展览。技术描述：为了在电子和光电设备中实现可重复的高性能，必须通过具有高结构单分散性的可扩展方法来生产纳米电子材料。此外，所得到的纳米电子材料组件需要被组装成能够保持其优异性能并且服从于后续制造方法的形态。为了实现这些目标，确定了分散化学、溶剂和密度梯度介质，使密度梯度超速离心法能够分选具有特殊结构和电子纯度的过渡金属二卤化物、氮化硼和黑磷。这些高纯度的样品促进了二维纳米电子材料作为结构参数(如厚度和横向尺寸)的函数的基础研究。此外，通过真空过滤和层层组装，将均匀的二维纳米材料分散体组装成多组分体异质结纳米复合薄膜和薄膜异质结构，适用于大面积纳米电子器件和电路的制备和测试。通过这种方式，在二维极限下阐明了表面和界面化学对电子性质的作用。

Nontechnical Description: With the increasing importance of portable and wearable electronic technologies, new materials are needed that combine superlative electronic properties with other requirements such as mechanical flexibility, low power consumption, and scalable manufacturing. Emerging two-dimensional nanoelectronic materials that are atomically thin meet many of these requirements, but no single material can achieve all of them concurrently. Consequently, this project develops heterostructures that synergistically integrate the desirable properties of multiple two-dimensional nanoelectronic materials, thus overcoming the design tradeoffs imposed by single materials utilized in isolation. Solution-processing methods are further employed to achieve highly homogenous nanoelectronic heterostructures in a manner that is compatible with large-scale, low-cost additive manufacturing. The results of this project are disseminated through a comprehensive set of education and outreach activities that include graduate curriculum development, undergraduate laboratories, and a materials science exhibit at the Chicago Museum of Science and Industry.Technical Description: To realize reproducibly high performance in electronic and optoelectronic devices, nanoelectronic materials must be produced via scalable methods that possess high structural monodispersity. Furthermore, the resulting nanoelectronic material components need to be assembled into morphologies that preserve their superior properties and are amenable to subsequent fabrication methods. Towards these goals, dispersion chemistries, solvents, and density gradient media are identified that enable density gradient ultracentrifugation sorting of transition metal dichalcogenides, boron nitride, and black phosphorus with exceptional structural and electronic purities. These high purity samples facilitate fundamental studies of two-dimensional nanoelectronic materials as a function of structural parameters such as thickness and lateral size. In addition, homogeneous two-dimensional nanomaterial dispersions are assembled via vacuum filtration and layer-by-layer assembly to form multi-component bulk heterojunction nanocomposite films and thin-film heterostructures that are suitable for the fabrication and testing of large-area nanoelectronic devices and circuits. In this manner, the role of surface and interfacial chemistry on electronic properties are elucidated at the two-dimensional limit.