EAPSI: Exploring Nano-scale Thermal Transport in Semiconductor Thin Films for the Advancement of Modern Electronic Devices

控制电子设备中的散热对于各种技术应用至关重要。近年来，纳米级电子器件的制造和利用的增长导致了对实现更小和更密集的电路的需求不断增加;因此，严重的热管理问题已成为当前半导体材料研究的焦点。一个这样的问题是两种半导体材料之间的界面充当热传输的屏障，因此显著降低了热导率。 该项目旨在通过研究半导体界面之间的热传输来了解并最终控制纳米尺度的热传输。薄膜厚度和界面粗糙度的热传输的依赖关系也将被检查。EAPSI研究员将与王璇博士合作进行实验和数据分析;王璇博士是北京中国科学院物理研究所和上海交通大学的超快电子衍射测量技术专家。本研究将利用飞秒电子衍射（FED）实验技术，对不同厚度的纳米薄膜进行真实的实时监测，研究纳米薄膜在超快加热后的温度变化。测量了热边界电导和声子约束对热输运的影响。FED直接真实的记录热晶格动力学和相干晶格动力学，从而获得比超快光学测量更相干的纳米尺度输运动力学图像。深入了解本项目中获得的纳米尺度热传输将有助于改善热管理，提高未来纳米器件的速度和功能。该项目将继续在中国发展FED，并为中国新提出的协同极端条件用户设施带来未来的研究合作，将FED推向世界级水平。NSF EAPSI奖是与中国科技部合作资助的。

Controlling heat dissipation in electronics is vital for a variety of technological applications. The recent growth of manufacturing and utilization of nano-scale electronics has led to the ever-increasing need to achieve smaller and denser circuits; thus serious thermal management issues have become the focus of current semiconductor material research. One such problem is that the interface between two semiconductor materials acts as a barrier to thermal transport, therefore dramatically decreasing thermal conductivity. This project seeks to understand and ultimately control thermal transport at the nanometer scale by investigating heat transport between semiconductor interfaces. The dependence of thermal transport on thin-film thickness and interface roughness will also be examined. The EAPSI fellow will perform the experiment and data analysis in collaboration with Dr. Xuan Wang; an expert in the measurement technique of ultra-fast electron diffraction, at the Institute of Physics, Chinese Academy of Sciences in Beijing and at Jiao Tong University in Shanghai, China. The findings of this project may offer new insight into the processes of nano-scale thermal transport and aid in the development of future nano-devices.This project will utilize the experimental technique of Femtosecond Electron Diffraction (FED) to monitor the nano-film temperature evolution after ultrafast heating in real time for various nano-film thicknesses. The thermal boundary conductance and the effect of phonon confinement on thermal transport will be measured. FED directly records both thermal and coherent lattice dynamics in real time, thus gaining a more coherent picture of nano-scale transport dynamics compared to ultrafast optical measurements. An in-depth understanding of nano-scale thermal transport gained in this project will help to improve thermal management and enhance the speed and function of future nano-devices. This project will continue to develop FED in China and give rise to future research collaboration for the newly proposed Synergetic Extreme Condition User Facility in China, pushing FED to a world-class level. This NSF EAPSI award is funded in collaboration with the Chinese Ministry of Science and Technology.