Optical, Electrical and Magnetic Properties of Multi-Cation Diamond-Like Semiconductors: Intricate Semiconductor Systems for Physical Property Tuning

多阳离子类金刚石半导体的光学、电学和磁学特性：用于物理特性调谐的复杂半导体系统

• 批准号: 1201729
• 负责人: Jennifer Aitken
• 金额: $ 43.1万
• 依托单位: Duquesne University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-06-01 至 2015-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1201729&HistoricalAwards=false
• 关键词: Optical; Electrical; Magnetic; Properties; Multi

TECHNICAL SUMMARY Multi-cation diamond-like semiconductors (DLSs) provide an excellent opportunity for physical property tuning since the number of potential compositions and chemical structures can be postulated using simple valence electron principles and Pauling's rules. This project will pursue a systematic approach to the synthesis and characterization of multi-cation DLSs, with a focus on second harmonic generation and thermoelectric properties. The multi-cation DLSs will be prepared by high-temperature solid-state synthesis, polychalcogenide flux synthesis, as well as iodine vapor transport reactions. The resulting materials will be characterized with an emphasis on structural studies via Rietveld refinement of neutron and/or X ray (laboratory or Synchrotron) powder diffraction data, single crystal X-ray diffraction, and electron diffraction, as well as other structural methods. The optical, electrical and magnetic properties of these new semiconductors will be systematically studied as a function of composition and structure. Experimentation will be complemented by theory, where electronic band structure calculations using density functional theory will be used to garner a deeper understanding of the physical properties. The ultimate goal of the project is to relate the crystal structure and electronic structure of these materials to the observed physical phenomena and identify the key structural elements that impart each material's unique characteristics. This research has the potential to bring us closer to the realization of new materials for specialized non-linear optical applications and thermoelectric devices that convert waste heat into useable energy. There is also a potential for finding multifunctional materials with uniquely combined properties for new and existing technologies, for example photo thermoelectrics or spintronics.NON-TECHNICAL SUMMARY This project, supported by the Solid State and Materials Chemistry program, aims to prepare and characterize multi-cation diamond-like semiconductors (DLSs) with potential second harmonic generation (SHG) and thermoelectric (TE) properties. DLSs are materials with structures resembling that of diamond, yet they are semiconducting in nature. Studies will focus on discovering why a particular compound possesses the observed physical properties. Through this knowledge, new materials can be designed with physical properties that are tuned for the desired application. DLSs with improved SHG response may find uses in medical, industrial and military applications such as laser frequency conversion and signal communications. DLSs with enhanced TE properties could be used for harnessing waste heat of the internal combustion engine and transforming it into energy. Improved TE materials are crucial to making the wide-scale usage of TE materials in home solid-state heating, ventilating and air-cooling systems a reality. Post-doctoral fellows, graduate students, undergraduate students, faculty from primarily undergraduate institutions, high school teachers and high school students will also participate in this project. The project will broaden the participation of groups that are traditionally underrepresented in sciences through the Project SEED program, a summer program for economically disadvantaged high school students, and the Women in Science program at Duquesne University. Additionally, collaborations with faculty and undergraduate students at primarily undergraduate institutions will take place through training and workshops on the usage and applications of cutting-edge materials characterization techniques such as single crystal X-ray diffraction.

多阳离子类金刚石半导体（DLS）提供了用于物理性质调节的极好机会，因为可以使用简单价电子原理和Pauling规则来假设潜在组成和化学结构的数量。本计画将以系统的方法来合成及表征多阳离子DLSs，著重于二次谐波产生及热电性质。将通过高温固相合成、多硫族化合物助熔剂合成以及碘蒸气传输反应来制备多阳离子DLSs。所得材料将通过中子和/或X射线（实验室或同步加速器）粉末衍射数据，单晶X射线衍射和电子衍射，以及其他结构方法的Rietveld细化结构研究的重点。这些新的半导体的光学，电学和磁学性质将作为组成和结构的函数进行系统研究。实验将通过理论来补充，其中使用密度泛函理论的电子能带结构计算将用于更深入地了解物理性质。该项目的最终目标是将这些材料的晶体结构和电子结构与观察到的物理现象联系起来，并确定赋予每种材料独特特性的关键结构元素。这项研究有可能使我们更接近于实现专门的非线性光学应用和热电设备，将废热转化为可用能量的新材料。还有一个潜在的新的和现有的技术，如光电或自旋电子学发现具有独特的综合性能的多功能材料。非技术摘要该项目，由固态和材料化学计划的支持，旨在制备和表征多阳离子类金刚石半导体（DLSs）与潜在的二次谐波产生（SHG）和热电（TE）性能。DLS是具有类似于金刚石的结构的材料，但它们本质上是半导体的。研究将集中在发现为什么一种特定的化合物具有观察到的物理性质。通过这些知识，可以设计出具有针对所需应用调整的物理特性的新材料。具有改进的SHG响应的DLSs可用于医疗、工业和军事应用，例如激光频率转换和信号通信。具有增强的TE性质的DLSs可用于利用内燃机的废热并将其转化为能量。改进的TE材料对于在家用固态加热、通风和空气冷却系统中大规模使用TE材料至关重要。博士后研究员、研究生、本科生、主要来自本科院校的教师、高中教师和高中学生也将参加这一项目。该项目将通过“种子项目”方案（一个针对经济困难高中生的暑期方案）和迪克讷大学的“妇女参与科学”方案，扩大传统上在科学领域代表性不足的群体的参与。此外，与主要本科院校的教师和本科生的合作将通过培训和研讨会来进行，这些研讨会涉及尖端材料表征技术（如单晶X射线衍射）的使用和应用。