Materials World Network: Science of Polar Homo- and Heterointerfaces

材料世界网络：极性同质和异质界面科学

• 批准号: 1108071
• 负责人: Jon-Paul Maria
• 金额: $ 60万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-15 至 2016-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1108071&HistoricalAwards=false
• 关键词: Materials; World; Network; Science; Polar

A focused international research collaboration linking North Carolina State University, the Technical University Berlin (TUB) and the Leibniz-Institut für Kristallzüchtung (IKZ) in Berlin, Germany, explores the fundamental science of epitaxial interfaces that define a discontinuity in electrical polarization in nitride-nitride and nitride-oxide systems. The aim is to understand the structural, chemical, and electronic features that regulate the interfacial electronic properties. The effort is based on a hypothesis that vertical and lateral heteropolar interfaces that approach 'semiconductor-grade' quality can be prepared, and that their study will lead to exciting opportunities for fundamental advances in interface physics and optic/electronic functionality. Each member of the international team brings a unique and leading edge technical capability that collectively enables this research. The Sitar group (NC State) brings a metalorganic chemical vapor deposition technology that can control polarity in thin films of nitride semiconductors both laterally and vertically; the Maria group (NC State) developed a surfactant-assisted molecular beam epitaxy technique that can for the first time prepare cubic oxides on GaN surfaces with a 2-D growth mode and dramatically reduced defect concentrations; the Hoffmann group (TUB) brings in optical characterization of polar materials and heterostructures; and the Albrecht group (IKZ) brings aberration-corrected transmission electron microscopy characterization with sub-Å spatial resolution and sub-eV energy resolution. The research refines synthesis techniques that enable hybrid thin film structures that seamlessly merge oxides and nitrides with heretofore unachievable material quality. By combining synthesis and characterization the investigators are able to identify and understand the structural and chemical features that enable, interfere, or enhance heteropolar interface coupling.Achieving an understanding of heteropolar interface-property relationships will propel research in hybrid systems that lead to new physics, new functionality, an expanded set of low dimension optoelectronic devices, and a pathway to smart structures that utilize in a new way the non-linear dielectric response of ferroelectrics. Through this collaboration, students and faculty from NCSU, TUB, and IKZ have access to mentoring expertise and world-class laboratory facilities in technical areas that are absent from the home institutions. U.S. and German students participate in a 6-month graduate sabbatical in program year three to ensure substantive international experience. During their first two years, U.S. students are encouraged take two semesters of German to acquire basic communication skills. The work of the German participants is supported by the German Research Foundation (DFG).

北卡罗来纳州立大学、柏林工业大学 (TUB) 和德国柏林莱布尼茨水晶研究所 (IKZ) 联合开展的一项重点国际研究合作，探索了定义氮化物中电极化不连续性的外延界面的基础科学。氮化物和氮氧化物系统的目的是了解调节界面电子特性的结构、化学和电子特征。可以制备接近“半导体级”质量的垂直和横向异极界面，他们的研究将为界面物理和光学/电子功能的基本进步带来令人兴奋的机会。 Sitar 小组（北卡罗来纳州）带来了一种金属有机化学气相沉积技术，可以横向和纵向控制氮化物半导体薄膜的极性；Maria 小组（北卡罗来纳州）开发了一种金属有机化学气相沉积技术。表面活性剂辅助分子束外延技术，首次以二维生长模式在 GaN 表面制备立方氧化物，并显着降低了缺陷浓度；霍夫曼组 (TUB) 引入了极性材料和异质结构的光学表征； Albrecht 小组 (IKZ) 带来了具有亚埃空间分辨率和亚电子伏能量分辨率的像差校正透射电子显微镜表征，该研究改进了合成技术，使混合薄膜结构能够无缝融合。通过结合合成和表征，研究人员能够识别和理解能够实现、干扰或增强异极界面耦合的结构和化学特征。了解异极界面-性质关系将推动研究。在混合系统中，导致新物理、新功能、一组扩展的低维光电器件以及以新方式利用非线性介电响应的智能结构的途径通过此次合作，NCSU、TUB 和 IKZ 的学生和教师可以获得美国和德国学生在技术领域所没有的指导专业知识和世界一流的实验室设施，并参加为期 6 个月的研究生休假。在项目第三年，为了确保实质性的国际经验，鼓励美国学生学习两个学期的德语，以获取基本的沟通技能。德国参与者的工作得到了德国研究基金会的支持。 （DFG）。