Materials World Network: Complex Structured "Electron-Poor" Framework Semiconductors With Potential For Thermoelectric Application

材料世界网：具有热电应用潜力的复杂结构“贫电子”框架半导体

• 批准号: 1007557
• 负责人: Dong-Kyun Seo
• 金额: $ 60万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-15 至 2014-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1007557&HistoricalAwards=false
• 关键词: Materials; World; Network; Complex; Structured

Thermoelectric devices cleanly convert heat into electricity through the Seebeck effect and can play an important role in satisfying the future global demand for efficient energy management. However, there exists a significant barrier to improving thermoelectric devices and that is the thermoelectric materials themselves. The most promising candidate materials are (heavily doped) narrow-gap semiconductors with low thermal conductivity. While crystal chemical mechanisms have been identified for reducing the thermal conductivity, a rationale selection of compositions and structures leading to bulk narrow-gap semiconductors is not well established. This international and interdisciplinary research program intends to advance thermoelectric materials research by uncovering new chemical compositions for bulk narrow-gap semiconductors, and by providing new understanding of chemical systems that border/overlap metals and semiconductors.The state-of-the-art thermoelectric material Zn4Sb3 is taken as a starting point and conceptually integrated into a larger class of chemical compounds ? electron poor framework semiconductors (EPFSs) ? which includes elemental boron at one extreme. EPFS materials, made from late transition metal, main group metal and semimetal atoms, form a common, weakly polar framework containing multi-center bonded structural entities. The localized multi-center bonding feature is thought to be the key to structurally complex semiconductors. Binary and ternary EPFS materials that have so far been identified and characterized show promising thermoelectric properties. Through a combination of chemical synthesis, structure analysis, computational modeling, and physical property measurements this Materials World Network (i) explores the compositional and structural potential of EPFS materials and (ii) analyzes their chemical bonding properties and the mechanisms behind band gap formation in complex structured intermetallics. The effort is among three institutions, Arizona State University (ASU, USA), Augsburg University (Germany), and Technical University Munich (Germany) and assembles a research group with faculty, staff and students from Chemistry and Physics departments. The merit of the international collaboration is a tight integration of the experimental and theoretical aspects of the research. This is paramount for unveiling the decisive structure-property correlations behind high thermoelectric performance. Participating students perform extensive research stays at the collaborating laboratories and benefit from expertise, techniques and instrumentation that is not available at their home institutions. The aim is to educate especially graduate students on the complexity of today?s materials research and immerse them in interdisciplinary and international research.

热电设备通过Seebeck效应将热量干净地转化为电力，并可以在满足未来对有效能源管理的全球需求方面发挥重要作用。但是，存在改善热电设备的重大障碍，即热电材料本身。最有前途的候选材料是（浓度掺杂的）狭窄的距离半导体，导热率低。虽然已经确定了降低导热率的晶体化学机制，但尚未确定导致较大狭窄半导体的组成和结构的基本原理选择。这项国际和跨学科研究计划打算通过揭示用于散装狭窄差异半导体的新化学成分，并提供对接壤/重叠金属和半导体的化学系统的新化学成分来推动热电材料研究。最先进的热电材料Zn4SB3是一个启动点和概念上的化学成分？电子较差的框架半导体（EPFSS）？其中包括一个极端的元素硼。 EPFS材料由晚期过渡金属，主体金属和半学原子制成，形成了一个常见的，弱极性框架，其中包含多中心键合结构实体。局部的多中心键合特征被认为是结构复杂的半导体的关键。迄今已鉴定出来的二元和三元EPFS材料表现出有希望的热电特性。通过化学合成，结构分析，计算建模和物理性能测量的结合，该材料世界网络（i）探讨了EPFS材料的组成和结构潜力，以及（ii）分析其化学键合特性以及在复杂结构上层金属中的频带隙形成背后的机制。这项工作是亚利桑那州立大学（美国国际航立大学），奥格斯堡大学（德国）和慕尼黑技术大学（德国）的三个机构中的努力，并与化学和物理部门的教职员工和学生组成了一个研究小组。国际合作的优点是研究的实验和理论方面的紧密整合。这对于揭示高热电性能背后的决定性结构 - 特性相关性至关重要。参与的学生在协作实验室进行广泛的研究，并受益于其家庭机构无法获得的专业知识，技术和仪器。其目的是教育特别的研究生，了解当今的材料研究的复杂性，并将其沉浸在跨学科和国际研究中。