Science and Schema for Directed Self-Assembly of Heteroepitaxial Quantum Dot Crystals Near the Intrinsic Length Scale

接近本征长度尺度异质外延量子点晶体定向自组装的科学和模式

• 批准号: 1410839
• 负责人: J. Floro
• 金额: $ 32.49万
• 依托单位: University of Virginia Main Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1410839&HistoricalAwards=false
• 关键词: Science; Schema; Directed; Self; Assembly

Non-technical Description: Synthetic quantum dot mesocrystals, i.e., three-dimensional (3D) periodic arrays of quantum dots (QDs) embedded in a matrix material, represent one strategy pertinent to designing new materials for nanoelectronics, thermoelectrics, optoelectronics, and magnetics, all areas that are critical to our technology-based economy. The project aims at establishing a deeper scientific basis for a specific approach to directed self-assembly relevant to various 3D periodic QDs systems that are often at the heart of electronic materials research and development. This type of synthesis has a great potential to reach unprecedented length scales. The effects of the highly-regimented nanostructure control on the resulting materials properties are explored. The outreach activities including curriculum development and the NanoDays are integrated with the research program. Technical Description: This research project focuses on the growth of synthetic quantum dot mesocrystals. These artificial materials are expected to have novel and improved properties. This research effort builds on the principal investigator's recent accomplishments in creating two-dimensional arrays of epitaxial Ge quantum dots on Si substrates. These highly uniform arrays formed by directed self-assembly on nanoscale surface templates. The templates are either periodic surface topography, or nanoscale "stressors," created by direct-write techniques. The two-dimensional quantum dot arrays serve as "seed crystals" for the formation of the three-dimensional mesocrystal by additional growth of Ge dot layers separated by Si interlayer spacers. No additional templating is required. The ultimate goal is to control self-assembly processes close to the intrinsic, limiting length scales associated with strain-driven quantum dot self-assembly. The resulting materials are structurally characterized, and their potential for novel electronic and thermal transport is explored.

非技术描述：合成量子点介晶，即嵌入基质材料中的量子点 (QD) 的三维 (3D) 周期性阵列，代表了一种与设计纳米电子学、热电学、光电子学和磁学新材料相关的策略，对我们的技术经济至关重要的所有领域。 该项目旨在为与各种 3D 周期性 QD 系统相关的定向自组装特定方法建立更深入的科学基础，这些系统通常是电子材料研究和开发的核心。 这种类型的合成具有达到前所未有的长度尺度的巨大潜力。探索了高度调节的纳米结构控制对所得材料性能的影响。包括课程开发和纳米日在内的外展活动与研究计划相结合。技术描述：该研究项目重点关注合成量子点介晶的生长。 这些人造材料有望具有新颖且改进的特性。这项研究工作建立在首席研究员最近在硅基板上创建二维外延Ge量子点阵列方面取得的成就的基础上。这些高度均匀的阵列是通过纳米级表面模板上的定向自组装形成的。 这些模板要么是周期性的表面形貌，要么是通过直写技术创建的纳米级“应力源”。二维量子点阵列充当“籽晶”，通过由 Si 层间间隔物分隔的 Ge 点层的额外生长来形成三维介晶。不需要额外的模板。 最终目标是控制自组装过程接近与应变驱动量子点自组装相关的固有的、有限的长度尺度。对所得材料进行了结构表征，并探索了它们在新型电子和热传输方面的潜力。