Femtosecond Laser Assisted MBE

本项目研究了在生长过程中暴露于高强度、超快激光脉冲(120飞秒)所导致的增强薄膜生长动力学的机制。将使用几种方法来评估原子化过程和机制。这些方法包括使用标志层直接测量结构细节及其空间变化(通过透射电子显微镜)、原位表面方法(LEED/RHEED/AES)以及各种其他化学和结构探针(X射线衍射、XEDS、EELS、AFM)。另一种技术，纳米温度计，将被探索来表征热效应作为距离被照射材料表面的距离的函数。纳米温度计的概念是一种不同材料的内生层，它以一种具有良好特性的方式扩散。通过测量这种层的扩散长度，可以推断出质量传输的“有效温度”。这个项目解决了材料科学中与技术相关的主题领域中的基础材料研究问题，并强调研究和教育的整合。该研究计划提供了在使用尖端科学设备方面的实践经验的绝佳机会。研究生和本科生将参与电子材料的合成、加工和表征。该项目还通过美国国家航空航天局/夏普在密歇根的互补性计划，为暑期与少数族裔学生的互动提供了一个协同工具。

This project addresses mechanisms that enhance thin film growth kinetics resulting from exposure to high intensity, ultrafast laser pulses (120 fs) during growth. Several methods will be utilized to assess atomistic processes and mechanisms. These include the use of marker layers to directly measure structural details and their spatial variations (via transmission electron microscopy-TEM), in-situ surface methods (LEED/RHEED/AES), as well as a variety of other chemical and structural probes (x-ray diffraction, XEDS, EELS, AFM). An additional technique, a NanoThermometer, will be explored to characterize thermal effects as a function of distance from the surface of the material being irradiated. The NanoThermometer concept is a grown-in layer of a different material that diffuses in a well-characterized manner. By measuring the diffusion length of such a layer, it is anticipated that an "effective temperature" for mass transport can be inferred. %%% This project addresses basic materials research issues in a topical area of materials science with technological relevance, and places emphasis on the integration of research and education. The research program provides excellent opportunities for hands-on experience in the use of sophisticated scientific equipment. Graduate and undergraduate students will be involved in the synthesis, processing, and characterization of electronic materials. This project also provides a synergistic vehicle for interaction with minority students during the summer through the complementary NASA/Sharp program at Michigan.***