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CAREER: Nanoscale temperature mapping across interfaces using scanning transmission electron microscopy

职业：使用扫描透射电子显微镜绘制跨界面的纳米级温度图

基本信息

批准号：
2145461
负责人：
Geoffrey Wehmeyer
金额：
$ 53.59万
依托单位：
William Marsh Rice University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2022
资助国家：
美国
起止时间：
2022-07-01 至 2027-06-30
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2145461&HistoricalAwards=false
关键词：
CAREER Nanoscale temperature mapping across

项目摘要

Interfaces between materials pose a major barrier to the thermal management of nanotechnologies ranging from transistors to light-emitting diodes and heat-assisted magnetic recording devices. Improvements in the fundamental understanding of nanoscale heat flow mechanisms across these interfaces could allow engineers to tailor the composition and structure of interfaces for optimized cooling strategies, leading to improved device durability and efficiency. However, it is currently difficult to test the predictions of competing interfacial thermal transport theories at the nanoscale because thermal experiments are not able to map temperature at the relevant near-atomistic lengthscales. This work will develop scanning transmission electron microscopy nanothermometry experiments and use atomistic calculations to elucidate the mechanisms of interfacial thermal transport and to provide high spatial resolution insight into the interface structure-thermal property relationship. This project will also build upon existing collaborations between Rice University and Houston-area community colleges to implement summer research experiences for community college students and to develop outreach events that promote career opportunities in nanotechnology and thermal management. The goal of this project is to test models for interfacial phonon heat transport by mapping temperature with sub-nanometer spatial resolution across strongly bonded interfaces. The nanothermometry measurements will leverage the temperature-dependent thermal diffuse scattering that has been detected in scanning transmission electron microscopy diffraction patterns and annular dark field images. This thermal diffuse scattering is directly related to the local atomic vibration amplitudes, which increase with increasing temperature. Calibrating and mapping the thermal diffuse scattering as a function of beam position will allow experiments with sub-nanometer electron beam diameters to measure the temperature profile with ultrahigh spatial resolution. These thermal electron microscopy experiments will be compared with theoretical predictions by combining atomistic modeling of temperature-dependent atomic vibrations near interfaces with multislice electron diffraction calculations to quantify the thermal diffuse scattering. The results will provide insight into the underlying physical mechanisms of interfacial thermal transport across semiconductor-semiconductor and semiconductor-metal junctions. Future application of this fundamental knowledge could allow engineers to improve the thermal design of interfaces in nanoelectronics and information storage technologies, with the goal of enabling more efficient device performance.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.

材料之间的界面对纳米技术的热管理构成了主要障碍，从晶体管到发光二极管和热辅助磁记录设备。对这些界面上纳米级热流机制的基本理解的改进可以使工程师能够定制界面的组成和结构以优化冷却策略，从而提高设备的耐用性和效率。然而，它是目前难以测试的预测，在纳米尺度上的竞争界面的热传输理论，因为热实验无法映射温度在相关的近原子的长度尺度。这项工作将开发扫描透射电子显微镜纳米测温实验，并使用原子计算来阐明界面热传输的机制，并提供高空间分辨率的界面结构-热性能的关系。该项目还将建立在赖斯大学和休斯顿地区社区学院之间的现有合作基础上，为社区学院学生提供夏季研究经验，并开发推广活动，促进纳米技术和热管理的就业机会。该项目的目标是通过在强键合界面上以亚纳米空间分辨率映射温度来测试界面声子热输运模型。纳米测温测量将利用温度相关的热扩散散射，已在扫描透射电子显微镜衍射图案和环形暗场图像中检测到。这种热漫散射与局部原子振动幅度直接相关，其随温度的升高而增加。校准和映射的热扩散散射作为一个功能的光束位置将允许实验与亚纳米电子束直径测量的温度分布与空间分辨率。这些热电子显微镜实验将与理论预测相结合的原子模型的温度相关的原子振动附近的界面与多层电子衍射计算，以量化的热漫散射。结果将提供深入了解跨半导体和半导体-金属结的界面热输运的基本物理机制。这一基础知识的未来应用将使工程师能够改进纳米电子和信息存储技术中接口的热设计，从而实现更高效的设备性能。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。