CAREER:Thermal Energy Transport in Organic-Inorganic Hybrid Materials

PI：Jonathan A. Malen，Carnegie Mellon UniversityProposal Number：CBET-1149374这个CAREER提案的目的是研究有机-无机杂化材料中的热传输。 有机-无机杂化材料是单晶半导体的有吸引力的替代品，用于电子，光子学和能量转换，因为它们可以用可扩展的基于溶液的工艺制造。对于这些应用，有机-无机界面已被用来控制电子传输，但热性能仍然没有培养。据推测，在有机-无机界面出现的集体性质将使混合材料中的热声子谱得到前所未有的控制。该提案的智力价值集中在两种新型混合材料：自组装单分子层（SAMs）和超晶格（NCSL）中的热传输实验测量。 SAM是在无机表面上形成的2-D分子晶体，NCSL是由有机分子间隔的无机球体的3-D阵列。有机和无机组分中不同振动态的耦合和排列可以通过化学控制以产生不同的热传输性质。 这些影响将通过以下方式进行实验研究：（i）开发一种新的连续波激光方法，以探测固体中声子平均自由程的无与伦比的范围，（ii）测量NCSL中的热导率和声子平均自由程分布，以及（iii）SAM界面热导的系统测量。操纵声子谱的能力将广泛影响能源领域的广泛应用。和生物学。 由于短的声子波长（10 nm），基于混合的声子光学器件将实现比具有长得多的波长的可见光高得多的分辨率。 这种非破坏性成像在生物、有机和无机样品的测定中非常有用。此外，基于溶液化学的制造和可调的电光特性使混合动力车成为需要广泛部署的能量转换技术的理想选择，包括热电、光电和LED。工程混合器件需要了解其迄今未知的热性能，而声子控制可以产生独特的性能升级。 自组装膜对声子的带通滤波可以提高光电子学的效率，而去耦的热和电子输运特性使NCSL成为热电废热转换的理想选择。一个旨在揭开声子神秘面纱的综合教育计划由“声子模拟器”突出显示，这是一个模拟物质振动的模型弹簧质量系统。这个教育工具包将与在线软件配对，并部署在整个匹兹堡公立学校（PPS），通过互动教育计划介绍热传递的起源。 当地的重点将是代表性不足的大学前学生从PPS以及学生在卡内基梅隆大学。 将通过英特尔国际科学工程博览会和西门子竞赛的讲习班进行更广泛的传播，目的是共同招募学者从事工程工作。

PI: Jonathan A. Malen, Carnegie Mellon UniversityProposal Number: CBET-1149374The objective of this CAREER proposal is to study thermal transport in organic-inorganic hybrid materials. Organic-Inorganic Hybrid Materials are attractive alternatives to single crystal semiconductors for electronics, photonics, and energy conversion because they can be manufactured with scalable solution-based processes. For these applications the organic-inorganic interface has been leveraged to control electronic transport, but thermal properties remain uncultivated. It is hypothesized that collective properties, emergent at the organic-inorganic interface, will enable unprecedented control of the thermal phonon spectrum in hybrid materials. The intellectual merit of the proposal centers around the experimental measurement of thermal transport in two novel hybrid materials: self assembled monolayers (SAMs) and nanocrystal superlattices (NCSLs). SAMs are 2-D molecular crystals that form on inorganic surfaces, and NCSLs are 3-D arrays of inorganic spheres spaced by organic molecules. Coupling and alignment of dissimilar vibrational states in the organic and inorganic components can be controlled by chemistry to yield diverse thermal transport properties. These effects will be experimentally interrogated through (i) the development of a new continuous-wave laser method to probe an unparalleled range of phonon mean free paths in solids, (ii) measurements of thermal conductivity and phonon mean free path distributions in NCSLs, and (iii) systematic measurements of SAM interface thermal conductance.The ability to manipulate the phonon spectrum will broadly impact a wide range of applications in energy and biology. Due to short phonon wavelengths (10 nm), hybrid based phonon-optics would achieve much higher resolution than visible light having much longer wavelengths. Such non-destructive imaging can be extremely useful in assays of biological, organic, and inorganic samples. Further, solution chemistry based manufacturing and tunable electro-optic properties make hybrids ideal for energy conversion technologies that demand wide deployment, including thermoelectrics, photovoltaics, and LEDs. Engineering hybrid devices requires knowledge of their hitherto unknown thermal properties, whereas phonon control can yield unique performance upgrades. Bandpass filtering of phonons by SAMs can increase the efficiency of optoelectronics, while decoupled thermal and electronic transport properties make NCSLs ideal for thermoelectric waste heat conversion. An integrated educational plan that aspires to demystify the phonon is highlighted by the "Phonon-Simulator", a model spring-mass system that simulates vibrations in matter. This educational kit will be paired with online software and deployed throughout the Pittsburgh Public Schools (PPS) to introduce the origins of heat transfer through an interactive educational program. The local focus will be underrepresented pre-college students from PPS as well as students at Carnegie Mellon. Broader dissemination will be achieved by workshops at the Intel International Science & Engineering Fair and the Siemens Competition, aimed at jointly recruiting scholars into engineering.