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CAREER: Probing the Thermal Relaxation Dynamics of Nanomaterials with Time-Resolved Calorimetry

职业：利用时间分辨量热法探索纳米材料的热弛豫动力学

基本信息

批准号：
2044788
负责人：
Dakotah Thompson
金额：
$ 53.42万
依托单位：
University of Wisconsin-Madison
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2021
资助国家：
美国
起止时间：
2021-02-01 至 2026-01-31
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2044788&HistoricalAwards=false
关键词：
CAREER Probing Thermal Relaxation Dynamics

项目摘要

The conversion of energy from one form to another is central to a number of emerging technologies such as solar cells and batteries. Nanoscale materials play a key role in the development of these technologies due to their unique electrical, optical, and thermal properties. However, energy conversion within nanomaterials is a complex and highly dynamic process that remains poorly understood. For example, the transient response of these materials to an external stimulus often results in the generation of heat over very short time scales of nanoseconds or less, which state-of-the-art experimental techniques are not able to fully characterize. In this proposal, a measurement approach will be developed that is capable of resolving these transient heat flow rates with both picowatt resolution and nanosecond response time. The insights obtained from these real-time measurements will not only enable improvements to the conversion efficiency of the devices introduced above, but will also unlock new classes of sensors and computer processors with higher bandwidth and lower power consumption. The proposed research will concurrently promote educational initiatives that will establish a pipeline for future researchers from south-central Wisconsin to become leaders in the field of thermal nanoscience and the larger STEM community. The PI proposes to develop an experimental platform that will enable real-time, room-temperature measurements of transient heat dissipation in nanomaterials as they relax over ultra-fast time scales. Although this measurement is extremely difficult due to the miniscule and rapidly-evolving heat signatures, it represents a crucial supplement to established pump-probe techniques and first-principles modelling approaches that will provide a detailed mapping of the relaxation pathways in these materials for the first time. The PI will leverage extensive technical expertise in nanofabrication, precision instrumentation, and thermal modelling to develop a novel calorimetric approach that is orders-of-magnitude more sensitive and more dynamic than the calorimetric techniques in use today. Using this platform, fundamental and technologically-relevant questions about the thermal relaxation dynamics of nanomaterials will be answered including, but not limited to, the following: What pathways are responsible for non-radiative recombination of excitons in quantum dots? How are structural phase transitions induced in polymorphic 2D materials? What role does magnon-phonon coupling play in the Bose-Einstein condensation of magnons within nanostructures?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.

将能量从一种形式转换为另一种形式是太阳能电池和电池等许多新兴技术的核心。纳米材料由于其独特的电学、光学和热学性质，在这些技术的发展中发挥着关键作用。然而，纳米材料中的能量转换是一个复杂且高度动态的过程，人们对其了解甚少。例如，这些材料对外部刺激的瞬态响应通常导致在纳秒或更短的非常短的时间尺度内产生热量，这是最先进的实验技术无法完全表征的。在这个建议中，将开发一种测量方法，能够解决这些瞬态热流率与皮瓦分辨率和纳秒响应时间。从这些实时测量中获得的见解不仅可以提高上述设备的转换效率，还可以解锁具有更高带宽和更低功耗的新型传感器和计算机处理器。拟议的研究将同时促进教育计划，这将为来自威斯康星州中南部的未来研究人员建立一个管道，成为热纳米科学领域和更大的STEM社区的领导者。PI建议开发一个实验平台，该平台将能够实时，室温测量纳米材料中的瞬态热耗散，因为它们在超快的时间尺度上放松。虽然由于微小和快速演变的热特征，这种测量是非常困难的，但它代表了对已建立的泵探测技术和第一原理建模方法的重要补充，将首次提供这些材料中弛豫路径的详细映射。PI将利用纳米纤维、精密仪器和热建模方面的广泛技术专长，开发一种新的量热方法，该方法比目前使用的量热技术更灵敏、更动态。使用这个平台，有关纳米材料的热弛豫动力学的基本和技术相关的问题将得到回答，包括但不限于以下内容：什么途径是负责量子点中激子的非辐射复合？如何在多晶二维材料中诱导结构相变？磁振子-声子耦合在奈米结构内磁振子的玻色-爱因斯坦凝聚中扮演什麽角色？该奖项反映了NSF的法定使命，并被认为是值得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的支持。