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.

能量从一种形式到另一种形式的转化是许多新兴技术（例如太阳能电池和电池）的核心。由于其独特的电气，光学和热性能，纳米级材料在这些技术的开发中起着关键作用。但是，纳米材料内的能量转化是一个复杂且高度动态的过程，仍然知之甚少。例如，这些材料对外部刺激的瞬时响应通常会导致纳秒或更少的短时间尺度上产生热量，哪种最先进的实验技术无法完全表征。在此提案中，将开发一种测量方法，能够通过Picowatt分辨率和纳秒响应时间解决这些瞬时热流速。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，而且还将解锁具有较高带宽和较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，该计划将为来自威斯康星州中南部的未来研究人员建立一条管道，以成为热纳米科学和较大STEM社区领域的领导者。 PI建议开发一个实验平台，该平台将在纳米材料中的瞬时散热器进行实时，室温测量，因为它们在超快速的时间尺度上放松。尽管由于微小和快速发展的热量特征，这种测量非常困难，但它代表了对已建立的泵探针技术和第一原理建模方法的关键补充，该方法将在这些材料中首次提供这些材料中放松途径的详细映射。 PI将利用广泛的技术专长，在纳米制作，精密仪器和热建模方面开发一种新型的热量量学方法，而比现在使用的量热法更敏感，更动态的量顺序。使用此平台，将回答有关纳米材料的热松弛动力学的基本和技术与技术相关的问题，包括但不限于以下内容：哪些途径是量子点中激素的非辐射重组的原因？多态2D材料中如何诱导结构相变？在纳米结构中，磁杆耦合在Bose-Einstein凝结中发挥了什么作用？该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子和更广泛影响的评估评估标准的评估值得支持的。