EAGER: Understanding Photochemical 2H-1T Phase Transition in Monolayer MoS2

EAGER：了解单层 MoS2 中的光化学 2H-1T 相变

• 批准号: 1649795
• 负责人: Ruoxue Yan
• 金额: $ 10万
• 依托单位: University of California-Riverside
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-15 至 2017-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1649795&HistoricalAwards=false
• 关键词: EAGER; Understanding; Photochemical; 2H; 1T

Non-technical Description: Ultra-thin transition metal dichalcogenides (TMDs) materials are promising candidates for flexible, low-power and transparent electronics and optoelectronics. Manipulating the atomic arrangements, referred to as crystal phases, can transform TMDs from semiconducting to metallic materials, which is a promising way to improve the overall device performance and/or to attain new functionalities. The current phase-engineering methods either rely on expensive and hostile chemicals or are incompatible with large-scale manufacturing. This project aims to develop a novel photochemical approach, which is controllable, scalable, low-cost, environmentally benign and compatible with electronic device fabrication, to induce phase-change in molybdenum disulfide. The research advances the state of knowledge of the phase-change mechanisms in TMD materials and explores the potential of TMD materials for applications in wearable electronics, foldable displays and lightings, and advanced integrated medical devices. The research effort is integrated with education and outreach activities, including training students in TMD materials, organizing a summer science camp and research internship programs for high school students that are traditionally underrepresented in the STEM field.Technical Description: This project proposes a novel photochemical concept for phase transition in monolayer molybdenum disulfide to address the pressing need for performance improvement in 2D-TMD based electronic/optoelectronic devices. The goal of this EAGER project is to understand photochemically induced 2H to 1T phase transformation in monolayer molybdenum disulfide and to establish processing-structure and structure-property correlations. In pursuit of this goal, the project objectives are to (1) validate the phase change mechanism through systematic characterizations of photo-chemically formed hetero-phase molybdenum disulfide and evaluate the controllability of the transition by varying processing parameters; (2) investigate the stabilization mechanism of the metastable metallic phase for improved device reliability; and (3) evaluate intriguing optical and electrical properties of phase-engineered molybdenum disulfide. Combined approaches of advanced structural characterization, optical analysis, device fabrication and electrical measurements are used in this research to gain fundamental understandings of the phase-change mechanism and the phase-engineered 2D-TMD materials.

非技术描述：超薄过渡金属二硫族化合物（TMDs）材料是柔性、低功耗、透明电子和光电子的有前途的候选者。操纵原子排列，即晶体相，可以将tmd从半导体材料转变为金属材料，这是提高整体设备性能和/或获得新功能的有希望的方法。目前的阶段工程方法要么依赖昂贵且有害的化学品，要么与大规模生产不相容。该项目旨在开发一种可控、可扩展、低成本、环保且与电子器件制造兼容的新型光化学方法，以诱导二硫化钼的相变。该研究推进了TMD材料相变机制的知识状态，并探索了TMD材料在可穿戴电子产品，可折叠显示和照明以及先进集成医疗设备中的应用潜力。研究工作与教育和推广活动相结合，包括培训学生使用TMD材料，组织暑期科学营和为传统上在STEM领域代表性不足的高中生提供研究实习项目。技术描述：本项目提出了一种新的光化学概念，用于单层二硫化钼的相变，以解决基于2D-TMD的电子/光电器件性能改进的迫切需求。这个EAGER项目的目标是了解光化学诱导的单层二硫化钼的2H到1T相变，并建立工艺-结构和结构-性能的相关性。为了实现这一目标，项目目标是：(1)通过光化学形成的异相二硫化钼的系统表征来验证相变机理，并通过不同的工艺参数评估相变的可控性；(2)研究亚稳金属相的稳定机制，提高器件可靠性；(3)评价相工程二硫化钼的光学和电学性能。本研究采用先进的结构表征、光学分析、器件制造和电学测量相结合的方法，以获得相变机制和相位工程2D-TMD材料的基本理解。

项目成果

Photochemically Induced Phase Change in Monolayer Molybdenum Disulfide

• DOI: 10.3389/fchem.2019.00442
• 发表时间: 2019-06-13
• 期刊: FRONTIERS IN CHEMISTRY
• 影响因子: 5.5
• 作者: Byrley, Peter;Liu, Ming;Yan, Ruoxue
• 通讯作者: Yan, Ruoxue

Capillary-Force-Assisted Clean-Stamp Transfer of Two-Dimensional Materials

• DOI: 10.1021/acs.nanolett.7b03449
• 发表时间: 2017-11-01
• 期刊: NANO LETTERS
• 影响因子: 10.8
• 作者: Ma, Xuezhi;Liu, Qiushi;Liu, Ming
• 通讯作者: Liu, Ming