Intrinsic Vacancy Chalcogenides for Spintronic Applications

用于自旋电子学应用的本征空位硫属化物

• 批准号: 0605601
• 负责人: Marjorie Olmstead
• 金额: $ 58.97万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-06-01 至 2010-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0605601&HistoricalAwards=false
• 关键词: Intrinsic; Vacancy; Chalcogenides; Spintronic; Applications

Technical: This project aims for fundamental understanding and modification of intrinsic-vacancy chalcogenide semiconductors for silicon compatible, spintronic applications. Experiments are planned to (i) incorporate transition metal (TM) impurities in A2 III B3 VI semiconductors, principally Ga2Se3, towards development of new dilute magnetic semiconductors and (ii) modulate interface kinetics and stoichiometries to control the band alignment when these new materials are grown epitaxially on a silicon substrate. Structure-property relationships of these largely unexplored materials will be investigated with a variety of characterization tools, including in situ scanning probe microscopy, photoelectron spectroscopy, and x-ray absorption spectroscopy and ex situ transport, magnetometry, x-ray and optical measurements, combined with theoretical calculations. The approach is to explore the physics and materials science of novel dilute magnetic semiconductors, where observation of quantum phenomena requires high materials quality and possibilities for device applications are controlled by nanoscale physics. Intrinsic vacancy chalcogenides contain flexible bonding constraints and multiple sites for magnetic dopant incorporation that may be controlled through heteroepitaxial growth. The resultant structural tunability creates a model system to test proposed magnetic mechanisms in dilute magnetic systems. This research is expected to advance knowledge regarding nanoscale mechanisms for controlling band offsets and film morphologies in intrinsic vacancy compounds. Research studies are planned to (i) determine the relative importance of free carriers and defects in controlling magnetism in these materials where carrier, magnetic species, and defect concentrations may be controlled independently; (ii) investigate the roles of mixed valence impurities and intrinsic structural vacancies in controlling nanostructure morphology and sites for dopant incorporation; and (iii) explore the role of interface stoichiometry in controlling both the band offset and the possibility of spin-polarized transport between silicon and these polar heterovalent materials. Anticipated outcomes include understanding of a new class of novel, Si-compatible, dilute magnetic semiconductors for use in new device technologies based on electron spin; and development of the means to control band-offsets at dissimilar materials interfaces. Non-Technical: The project addresses basic research issues in a topical area of materials science having high potential technological relevance. The research will contribute materials science knowledge at a fundamental level to new understanding and capabilities in electronic devices. The research promotes further miniaturization and multifunctionalization of Si-based technologies. An important feature of the program is the integration of research and education through the training of students in a fundamentally and technologically significant area. Students at the undergraduate, masters, doctoral and post-doctoral level will learn to bridge disciplines and cultures as they work at the interface between science and engineering in the development of new paradigms, new science and new technologies. Through direct participation at the research frontier, students will acquire essential, transferable skills for their future participation in the scientific and technological workforce. The project strengthens other NSF-funded education efforts at the University of Washington (UW) through the principal investigators' involvement in the Nanotechnology Ph.D. Program (IGERT), UW/PNNL Joint Institute for Nanoscience, and Summer Research Experience for Undergraduates. The principal investigators have demonstrated commitment to advancing the participation of women and minorities in the sciences and engineering, including developing a course and lecture series on these issues, participating in the UW Minority Science and Engineering Program and new centralized science and engineering minority graduate student recruiting, serving on UW's NSF-ADVANCE leadership team, and working in community science education projects. Expertise and visibility gained through this research project provides a synergistic basis for success of such outreach and educational activities.

技术：该项目旨在从根本上理解和修改本征空位硫族化物半导体，以实现硅兼容的自旋电子应用。计划进行实验：(i) 在 A2 III B3 VI 半导体（主要是 Ga2Se3）中加入过渡金属 (TM) 杂质，以开发新型稀磁半导体；(ii) 调节界面动力学和化学计量，以控制这些新材料在硅衬底上外延生长时的能带排列。这些很大程度上未经探索的材料的结构-性能关系将通过各种表征工具进行研究，包括原位扫描探针显微镜、光电子能谱、X射线吸收光谱以及异位传输、磁力测定、X射线和光学测量，并结合理论计算。该方法旨在探索新型稀磁半导体的物理和材料科学，其中量子现象的观察需要高材料质量，并且器件应用的可能性由纳米级物理控制。本征空位硫族化物包含灵活的键合约束和多个可通过异质外延生长控制的磁性掺杂剂掺入位点。由此产生的结构可调性创建了一个模型系统来测试稀磁系统中提出的磁机制。这项研究预计将增进有关控制本征空位化合物中能带偏移和薄膜形态的纳米级机制的知识。计划进行研究：(i) 确定自由载流子和缺陷在控制这些材料的磁性方面的相对重要性，其中载流子、磁性物质和缺陷浓度可以独立控制； (ii) 研究混合价杂质和固有结构空位在控制纳米结构形态和掺杂剂掺入位点中的作用； (iii)探索界面化学计量在控制带偏移以及硅和这些极性异价材料之间自旋极化传输的可能性方面的作用。预期成果包括了解一类新型、与硅兼容的稀磁半导体，用于基于电子自旋的新器件技术；以及开发控制不同材料界面处的带偏移的方法。非技术性：该项目解决具有高度潜在技术相关性的材料科学主题领域的基础研究问题。该研究将从根本上贡献材料科学知识，以促进对电子设备的新理解和能力。该研究促进了硅基技术的进一步小型化和多功能化。该计划的一个重要特点是通过在基础和技术重要领域对学生进行培训，将研究和教育结合起来。本科生、硕士、博士和博士后级别的学生将在科学与工程的交叉点上工作，开发新范式、新科学和新技术，从而学习在学科和文化之间架起桥梁。通过直接参与前沿研究，学生将获得必要的、可转移的技能，为他们未来参与科技劳动力提供帮助。该项目通过主要研究人员参与纳米技术博士学位项目，加强了华盛顿大学 (UW) 的其他 NSF 资助的教育工作。项目 (IGERT)、威斯康星大学/太平洋西北国家实验室纳米科学研究所联合项目以及本科生暑期研究经验。主要研究人员表现出了促进女性和少数族裔参与科学和工程的承诺，包括开发有关这些问题的课程和系列讲座、参与威斯康星大学少数族裔科学与工程计划和新的集中科学与工程少数族裔研究生招募、在威斯康星大学 NSF-ADVANCE 领导团队中任职，以及参与社区科学教育项目。通过该研究项目获得的专业知识和知名度为此类外展和教育活动的成功提供了协同基础。