van der Waals mediated interaction dynamics between individual nanostructures

广泛用于电信、计算和能量转换应用的现代微电子设备依赖于不断缩小的特征尺寸，其中材料在原子尺度上被操纵，并表现出新的和极端的特性。随着特征长度的减少，材料之间的界面开始主导材料的性能，因此也主导了器件的性能。然而，我们对电荷和热量如何通过这些界面传递的理解仍然有限。为了创造更好的材料和器件，我们必须研究界面对载流子输运的影响，这是导致这些高尺度结构表现出极端特性的原因。该项目将测量通过几个精心控制的界面的能量流，并使用原子尺度建模预测这些界面的性能。理论和实验相结合的方法将为创造和优化未来的设备产生新的设计规则。因此，这个项目的结果具有深远的影响，可以减少我们的能源消耗，更快的计算机，增加通信带宽。缺乏对界面声子输运的深入理解是当前复合材料微电子冷却和热设计的瓶颈。本项目旨在了解单个纳米结构之间范德华界面的相互作用动力学，这决定了这些界面上声子的传输和散射机制。范德华界面的相互作用动力学会改变声子的透射系数，导致单带和双带之间的热导率不同。因此，我们的方法是系统地测量单个硅纳米带、硅双纳米带和硅硼双纳米带的固有导热系数，并进行相应的原子尺度建模。比较不同样品的结果将提供新的见解，了解不同因素，如粘附能，声阻抗失配和非晶态层如何影响声子通过范德华界面的传输，这将为通过这些界面操纵热传输提供新的见解。由于范德华界面是单个纳米结构或纳米结构与衬底/主体材料之间最常见的界面之一，因此获得的基本理解将阐明如何更好地管理微电子器件中的散热和调整纳米复合材料的热性能。

CBET-1403456WalkerModern microelectronic devices extensively used in telecommunications, computing, and energy conversion applications rely on ever shrinking feature sizes where materials are manipulated at atomic scale and exhibit new and extreme properties. As characteristic lengths decrease, interfaces between materials begin to dominate the performance of the materials, and hence the devices. Yet, our understanding of how charge and heat transmit through these interfaces is still limited. To create better materials and devices, we must study the effects of interfaces on carrier transport that are responsible for the extreme properties these highly scaled structures exhibit. This project will measure the flow of energy through several carefully controlled interfaces and predict the performance of those interfaces using atomistic-scale modeling. The combined theoretical and experimental approach will produce new design rules for creating and optimizing future devices. Consequently, the results of this project have far reaching implications and could lead to a reduced drain on our energy resources, faster computers, and increased communication bandwidth.The lack of thorough understanding of interfacial phonon transport is a current bottleneck in microelectronic cooling and thermal design of composite materials. This project aims at understanding the interaction dynamics of van der Waals interfaces between individual nanostructures, which determines the phonon transmission and scattering mechanisms at these interfaces. The interaction dynamics at the van der Waals interface will alter the phonon transmission coefficient, leading to different thermal conductivities between single and double ribbons. Therefore, our approach is to measure systematically the intrinsic thermal conductivity of individual silicon nanoribbons, silicon double nanoribbons, and silicon and boron double ribbons, and to perform corresponding atomic scale modeling. Comparison of results from different samples will provide new insights into how different factors, such as adhesion energy, acoustic impendence mismatch, and amorphous layers affect phonon transmission through van der Waals interfaces, which will provide new insights into manipulating thermal transport through these interfaces. Since van der Waals interfaces are one of the most common interfaces between individual nanostructures or nanostructures and substrates/host materials, the obtained fundamental understanding will shed light on how to better manage the heat dissipation in microelectronic devices and tune the thermal properties of nanocomposites.