Extraordinary Radiative Transfer through Hyperbolic Material and at Interface

几个世纪以来，辐射一直被认为是一种跨越空间的热传递过程，而这种过程在材料内部的速率要比传导慢得多。拟议的项目将调查新发现的，大大增强辐射传输在一种被称为双曲材料的材料。所提出的研究将有助于对材料内部和不同类型材料和器件之间这种新的辐射传递过程的基本理解。近年来迅速发展和发现的新材料，包括双曲材料，在推进现代技术，包括光子学，电子学，能量转换和未来量子技术方面显示出巨大的希望。加强传热将显著影响基于这些新材料的技术发展，因为传热对这些材料和设备的性能至关重要。该项目还将在人力资源开发方面作出重大努力，包括在新兴工程领域培养研究生和本科生，根据最新研究成果扩大本科教育，以及向小学至高中学生推广。提出的项目建立在热输运研究方面的广泛专业知识的基础上，特别是最近发现的双曲材料中显著的辐射输运，这是由大量传播的能量携带模式（称为双曲声子极化子）实现的。本文将采用多种先进的计算和实验方法，结合理论/计算和实验研究，详细研究这一新传热过程的基本原理，包括：(1)光谱和温度相关辐射输运的理论研究；(2)温度相关、光谱和空间辐射输运和总辐射输运的实验测量；(3)大大增强了纳米间隙的辐射传递；(4)大大增强了辐射跨材料和器件的输运。总的来说，这些研究将增强对辐射传输基础和限制的理解，并指导工程应用的热设计或协同设计。本项目研究的课题可以扩展到其他科学和工程领域，包括用于高分辨率成像和传感的小尺度辐射，用于医疗的红外辐射源，以及先进的电子、光子和能量收集设备的设计。该奖项反映了美国国家科学基金会的法定使命，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。

For centuries, radiation has been considered a heat transfer process across space, with rates of this process inside a material being much slower than conduction. The proposed project will investigate newly discovered, greatly enhanced radiative transfer inside a type of material called hyperbolic material. The proposed research will contribute to the fundamental understandings of this new radiative transfer process inside materials and across different types of materials and devices. The recent rapidly developed and discovered new materials including hyperbolic materials have shown great promises in advancing modern technologies including photonics, electronics, energy conversion, and future quantum technologies. Enhancing heat transfer will significantly impact technology developments based on these new materials as heat transfer is vital for the performance of these materials and devices. This project will also have significant efforts in human resource development, including contributions to training of graduate and undergraduate students in emerging engineering areas, expanding undergraduate education based on newest research results, and outreach to elementary-to-high school students.The proposed project is built upon extensive expertise in thermal transport studies, especially the recent discovery of significant radiative transport in hyperbolic materials enabled by a large number of propagating energy carrying modes called hyperbolic phonon polaritons. The proposed work will investigate fundamentals of this new heat transfer process in detail by combined theoretical/computational and experimental studies, with the use of many advanced computational and experimental methods, including: (1) theoretical studies of spectral and temperature dependent radiative transport; (2) experimental measurements of temperature dependent, spectral and spatial radiative transport and total radiative transport; (3) greatly enhanced radiative transfer across nanometer-size gaps; (4) greatly enhanced radiative transport across materials and devices. Collectively, these studies will enhance understanding of the fundamentals and the limits of radiative transfer and to guide thermal design or co-design for engineering applications. The subjects studied in this project can be extended to other fields of science and engineering, including radiation at small scales for high resolution imaging and sensing, infrared radiation sources for medical use, and design of advanced electronic, photonic, and energy harvesting devices.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.