Buried Single Crystal Semi-Metal/Semiconductor Nanocomposites for 3D Electronic Materials

用于 3D 电子材料的埋入式单晶半金属/半导体纳米复合材料

• 批准号: 1507875
• 负责人: Christopher Palmstrom
• 金额: $ 39万
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2019-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1507875&HistoricalAwards=false
• 关键词: Buried; Single; Crystal; Semi; Metal

Nontechnical Description: This project investigates a new class of crystalline metal-semiconductor nanostructure composites. Because of their unique 3-dimensional (3D) nanostructures, these nanocomposite materials have the potential for practical applications for enabling new semiconductor devices, thermoelectrics, photodetectors, and terahertz technologies with broad impacts to society. The mechanism by which these 3D nanostructure composites form is studied by combining atomic-level control of growth with structural and electronic characterization. Changes in growth conditions, such as the proportion of metal to semiconductor components, the growth temperature, substrates with various crystal orientations, and different metal-semiconductor combinations, result in new nanostructures with different properties. The effects of these parameters on growth are modeled and then used to design new materials. This research involves graduate students and postdoctoral associates in interdisciplinary research areas of materials science, electrical engineering, condensed matter and materials physics, and chemistry. In addition, participants of this project are engaged in a variety of educational activities from high-school through graduate level and beyond, which brings people of all ages and under-represented communities into contact with STEM opportunities. Technical Description: The main objective of the project is to establish a fundamental understanding of a surface mediated thermodynamic phase separation mechanism that occurs during the molecular beam epitaxial (MBE) growth of GaSb, GaAs and related compound semiconductors with co-deposition of a rare-earth (RE) element such as Er. The MBE co-deposition results in the formation of embedded epitaxial semi-metallic RE-V rods, branched trees and two-dimensional sheets. Further study includes determining the physical properties of these nanostructures and exploring their potential applications as buried contacts in photodetectors. In-situ atomic level structural, chemical and electronic characterization tools, including scanning tunneling microscopy and spectroscopy plus X-ray photoelectron spectroscopy, are combined with MBE growth to study the growth mechanism at the atomic scale. The electronic and optical properties are studied ex-situ by temperature-dependent magnetotransport, photoluminescence and terahertz (THz) spectroscopy. The fundamental materials exploration of these nanostructured materials could enable future applications as buried contacts for stacked photodetectors and terahertz polarization filters, detectors, and sources.

非技术描述：该项目研究了一类新的晶体金属-半导体纳米结构复合材料。由于其独特的三维（3D）纳米结构，这些纳米复合材料具有实际应用的潜力，使新的半导体器件，热电，光电探测器和太赫兹技术对社会产生广泛的影响。这些3D纳米结构复合材料形成的机制进行了研究，结合原子级控制的增长与结构和电子表征。生长条件的变化，例如金属与半导体组分的比例、生长温度、具有各种晶体取向的衬底以及不同的金属-半导体组合，导致具有不同性质的新纳米结构。这些参数对生长的影响进行建模，然后用于设计新材料。这项研究涉及材料科学，电气工程，凝聚态物质和材料物理学以及化学等跨学科研究领域的研究生和博士后。此外，该项目的参与者参与了从高中到研究生及以上的各种教育活动，使所有年龄段的人和代表性不足的社区接触STEM机会。技术说明：该项目的主要目标是建立一个表面介导的热力学相分离机制，发生在分子束外延（MBE）生长的GaSb，GaAs和相关的化合物半导体与共沉积的稀土（RE）元素，如Er的基本理解。MBE共沉积导致形成嵌入式外延半金属RE-V棒、树枝和二维片。进一步的研究包括确定这些纳米结构的物理性质，并探索其作为光电探测器中的掩埋接触的潜在应用。原位原子水平的结构，化学和电子表征工具，包括扫描隧道显微镜和光谱加上X射线光电子能谱，与MBE生长相结合，研究在原子尺度上的生长机制。电子和光学性质的研究异位温度依赖的磁输运，光致发光和太赫兹（THz）光谱。这些纳米结构材料的基础材料探索可以使未来的应用程序作为堆叠的光电探测器和太赫兹偏振滤波器，探测器和源的掩埋接触。