growth and structure determination of thin films for future electronic technologies

许多新兴或未来的技术依赖于材料的原子级控制，而这些材料的优化反过来又需要对材料特性的原子级理解。这在与微电子相关的应用中尤其如此，其中关键器件性能取决于从单个原子层到亚微米尺度的长度尺度上的材料、表面和界面的详细特性。在这个建议中，我们将利用新获得的低温扫描隧道显微镜（STM），扩大我们以前的研究范围的表面和薄膜的原子结构的两个应用领域。** 首先是研究与有机电子器件（如有机发光二极管）性能相关的分子界面。这些器件的性能可以取决于单个分子层生长的确切方式。一些差异归因于分子在这些边界处的相对取向，但这方面的证据仅在少数系统中得到证实。我们将研究一系列广泛的分子界面，部分由低温STM实现，这将限制成像时表面上分子的运动，并且还将实现更可靠的光谱测量。我们还将把这项工作扩展到分子掺杂剂系统，这些系统越来越多地用于最新一代的有机电子器件。通过详细了解这些接口的结构所提供的见解将导致更好的基本理解，并将使这项技术得到进一步改进。第二个领域是表面和薄膜的研究，表现出自旋敏感的电子结构，由于Rashba效应，在自旋电子学的潜在未来应用。 重点将是探测生长薄膜的性质，其中重金属原子的周期性排列可以通过半导体衬底的表面重建来创建。这将提供比通过观察拓扑绝缘体的本体终止表面或含重金属的2D层状化合物的表面可获得的更广泛的原子结构。我们还将关注缺陷对表面的影响，这对这些材料的未来应用至关重要。** 在这两个领域的工作之间的联系是STM在原子分辨率上提供的结构和光谱信息。通过与其他两个小组的密切合作，这些信息将在一种情况下导致更好的有机电子器件性能，在另一种情况下，开发具有自旋相关特性的新材料，用于自旋电子学的未来应用。

Many emerging or future technologies depend on the atomic level control of materials, and the optimization of such materials requires, in turn, an atomic level understanding of the materials properties. This is particularly true in applications related to microelectronics, where critical device performance depends on the detailed properties of materials, surfaces, and interfaces on length scales from individual atomic layers up to the sub micron scale. In this proposal, we will take advantage of a newly acquired low temperature scanning tunneling microscope (STM) to broaden the scope of our previous research on the atomic structure of surfaces and thin films to two areas of application. ******The first is the study of molecular interfaces relevant to the performance of organic electronic devices such as organic light emitting diodes. The performance of these devices can depend on the exact manner in which individual layers of molecules are grown. Some of the differences have been attributed to the relative orientations of molecules at such boundaries, but evidence for this has been demonstrated in only a handful of systems. We will study a broad set of molecular interfaces, enabled in part by cryogenic STM which will restrict the motion of molecules on the surface while imaging, and will also enable more reliable spectroscopic measurements. We will also extend this work to molecular dopant systems, which are increasingly being used in the latest generation organic electronic devices. The insights provided by a detailed knowledge of the structure of these interfaces will lead to a better fundamental understanding, and will enable further improvements in this technology.******The second area is the study of surfaces and thin films that exhibit spin sensitive electronic structure due to the Rashba effect, with potential future applications in spintronics. The emphasis will be on probing the properties of grown thin films where periodic arrangements of heavy metal atoms can be created via surface reconstructions of semiconductor substrates. This will provide a wider variety of atomic structures than would be available by looking at either the bulk terminated surfaces of topological insulators, or the surfaces of heavy metal containing 2D layered compounds. We will also focus on the influence of defects on surfaces, which will be vital for the future applications of these materials. ******What links the work in both areas is the structural and spectroscopic information provided at atomic resolution by STM. Through close collaboration with two other groups, this information will lead in one case to better organic electronic device performance, and in the other, development of new materials with spin dependent properties for future applications in spintronics.