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

控制电子产品的散热对于各种技术应用是至关重要的。近年来，随着纳米电子制造和应用的增长，人们越来越需要实现更小、更密集的电路，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了热传输的屏障，因此大大降低了导热系数。该项目试图通过研究半导体界面之间的热传输来理解并最终控制纳米尺度上的热传输。热传输对薄膜厚度和界面粗糙度的依赖关系也将被考察。EAPSI研究员将与王轩博士合作进行实验和数据分析。王轩博士是北京中科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中国博士。本项目将利用飞秒电子衍射(FED)实验技术，实时监测不同厚度的纳米薄膜在超快加热后的温度变化。将测量热边界电导和声子限制对热输运的影响。FED直接实时记录热和相干晶格动力学，因此与超快光学测量相比，获得了更相干的纳米尺度输运动力学图像。通过本项目对纳米尺度热输运的深入了解，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开发FED，并为新提出的中国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。该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.