Alternative transducer and optical pumping scheme for nanoscale thermal metrology and imaging

用于纳米级热计量和成像的替代传感器和光泵浦方案

• 批准号: 2315077
• 负责人: Peijun Guo
• 金额: $ 40.29万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2315077&HistoricalAwards=false
• 关键词: Alternative; transducer; optical; pumping; scheme

Heat dissipation is intrinsic to technologies ranging from micro- and power-electronics to energy-storage devices and thermoelectrics. The ability to characterize and understand thermal transport processes can help regulate the flow of heat and improve device functionality, efficiency, and stability, especially for those made of materials with poor thermal conductivities. Nonetheless, measuring thermal transport in low thermal-conductivity materials at a high spatial resolution is still challenging. A new approach is proposed here, in which the heat flow will be directly imaged by a high-speed camera with spatial resolution down to hundreds of nanometers. The proposed approach is laser-based, hence non-contact, and will take advantage of organic semiconducting materials, which are abundant and ubiquitously used in organic light-emitting diodes and displays. The organic semiconductors will serve as local temperature reporters of materials underneath, whose thermal conductivity can be assessed by observing how quickly the temperature of the organic semiconductor varies in time. The project will provide extensive training opportunities to graduate and undergraduate students in the construction and modification of comprehensive optical measurement systems with high spatial and temporal resolution. K-12 students from local public high schools will gain understanding and experience in state-of-the-art thermal metrology experiments.Defects, grain boundaries, among other types of inhomogeneities are characteristics of materials that are not single crystals or epitaxial films. To understand the influence of such imperfections on heat transport in emerging energy-related materials, the team will explore organic semiconductors as an alternative type of transducer for optical pump-probe thermoreflectance measurements. The morphology, optical properties, and thermal transport properties of several prototypical organic semiconductors will be thoroughly investigated over a wide temperature range. Meanwhile, a time-resolved, wide-field optical imaging setup will be constructed, which will permit efficient thermal excitation of organic transducers and their accurate temperature monitoring with nanosecond time resolution. The team will perform proof-of-concept experiments to spatiotemporally imaging the flow of heat in heterogeneous energy materials and in prototypical two-dimensional ferromagnetic materials. It is expected that the alternative transducer and imaging technique proposed here can complement the existing thermoreflectance techniques for the investigation of thermal transport properties of a wide range of technologically important materials used for energy conversion and storage, optoelectronics, and beyond. The ability to remove the transducer after their use is a useful feature for measuring unreproducible or high-value samples, and for failure analysis and quality control of semiconductor chips.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.

散热是从微电子和电力电子到能量存储设备和热电技术的固有技术。表征和理解热传输过程的能力可以帮助调节热量流动并提高设备功能、效率和稳定性，特别是对于由导热性较差的材料制成的设备。尽管如此，以高空间分辨率测量低导热率材料中的热传输仍然具有挑战性。这里提出了一种新方法，其中热流将由空间分辨率低至数百纳米的高速相机直接成像。所提出的方法是基于激光的，因此是非接触式的，并将利用有机半导体材料，有机半导体材料丰富且普遍用于有机发光二极管和显示器。有机半导体将充当下方材料的局部温度报告器，可以通过观察有机半导体的温度随时间变化的速度来评估其热导率。该项目将为研究生和本科生提供广泛的培训机会，帮助他们构建和修改具有高空间和时间分辨率的综合光学测量系统。来自当地公立高中的 K-12 学生将在最先进的热计量实验中获得了解和经验。缺陷、晶界以及其他类型的不均匀性是非单晶或外延膜材料的特征。为了了解此类缺陷对新兴能源相关材料中热传输的影响，该团队将探索有机半导体作为光学泵浦探针热反射测量的替代传感器。几种原型有机半导体的形貌、光学性质和热传输性质将在很宽的温度范围内得到彻底研究。同时，将构建时间分辨的宽视场光学成像装置，这将允许有机换能器的有效热激发及其以纳秒时间分辨率进行精确的温度监测。该团队将进行概念验证实验，对异质能源材料和原型二维铁磁材料中的热流进行时空成像。预计这里提出的替代换能器和成像技术可以补充现有的热反射技术，用于研究用于能量转换和存储、光电子学等的各种技术重要材料的热传输特性。使用后拆卸传感器的能力对于测量不可重现或高价值样品以及半导体芯片的故障分析和质量控制来说是一个有用的功能。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准。