RUI: Electronic Properties of Finite Molecular Layer Transition Metal Dichalcogenides

RUI：有限分子层过渡金属二硫属化物的电子性质

• 批准号: 1410496
• 负责人: Andrew Stollenwerk
• 金额: $ 24.73万
• 依托单位: University of Northern Iowa
• 依托单位国家: 美国
• 项目类别: Continuing 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=1410496&HistoricalAwards=false
• 关键词: RUI; Electronic; Properties; Finite; Molecular

Non-Technical: The goal of this project is to better understand the electronic and optical properties of thin sheets of materials with thickness in the range of a few atomic layers. These properties have practical applications in solar cells, light emitting diodes (LEDs), and a wide variety of sensors. A multidisciplinary approach is used to obtain a more complete picture necessary to use these materials in these applications. This research involves undergraduate students trained on a wide variety of techniques that involve electronics, optics and chemistry. Such an environment results in well-rounded students ready for careers in either industry or academia. The University of Northern Iowa provides an excellent opportunity for this project to have a positive impact on elementary, middle, and high school students from diverse backgrounds throughout Iowa and surrounding states. Regular contact with high school science teachers allows faculty research activities and student opportunities to be showcased directly. Such efforts encourage students to explore careers in STEM (science, technology, engineering, and mathematics) fields. Technical: The goal of this project is to develop a more thorough understanding of the electronic and optical properties of a wide variety of finite layer dichalcogenide molecular sheets. Ultrasonic agitation is used to break apart these layered crystals from the bulk into thin nano-sheets. Those sheets with the smallest number of layers are separated using a centrifuge and studied using scanning tunneling microscopy, optical spectroscopy, and ballistic electron emission microscopy. Scanning tunneling microscopy measurements serve to study topological features as well as surface electrical properties on the atomic scale. This includes the zero resistance characteristics associated with charge density waves in two-dimensional dichalcogenides sheets. Raman and photoluminescence complement the electrical measurements made using the localized probe of the scanning tunneling microscope, providing global information on electronic band structure and vibrational properties. Transport measurements are achieved by injecting electrons into these structures using ballistic electron emission microscopy, allowing characterization of electron scattering as a function of temperature and energy. Together, these combined data will enable a more complete understanding of reduced dimensionality on the electronic properties in a wide variety of material systems. More importantly, broadening the research focus of this field to a more diverse array of layered materials will enhance our understanding of the fundamental physics in two-dimensional systems. Modifications of current theories to encompass a wider variety of layered materials leads to more robust theoretical models, essential to device design.

非技术：该项目的目标是更好地了解厚度在几个原子层范围内的薄片材料的电子和光学特性。 这些特性在太阳能电池、发光二极管（LED）和各种传感器中具有实际应用。 一个多学科的方法是用来获得一个更完整的图片需要在这些应用中使用这些材料。 这项研究涉及接受过各种技术培训的本科生，这些技术涉及电子，光学和化学。 这样的环境导致全面发展的学生准备在行业或学术界的职业生涯。 北方爱荷华州的大学提供了一个很好的机会，这个项目有一个积极的影响，小学，初中和高中学生来自不同背景的整个爱荷华州和周边国家。 与高中科学教师定期接触，使教师的研究活动和学生的机会，直接展示。 这些努力鼓励学生探索STEM（科学，技术，工程和数学）领域的职业生涯。 技术支持：这个项目的目标是发展一个更深入的了解各种各样的有限层二硫属化合物分子片的电子和光学性质。 超声波搅拌用于将这些层状晶体从块体分解成薄的纳米片。 使用离心机分离具有最小层数的那些片材，并使用扫描隧道显微镜、光学光谱和弹道电子发射显微镜进行研究。 扫描隧道显微镜测量用于在原子尺度上研究拓扑特征以及表面电学性质。 这包括零电阻特性与二维dichalcogenides片的电荷密度波。 拉曼和光致发光补充了使用扫描隧道显微镜的本地化探针进行的电学测量，提供了关于电子能带结构和振动特性的全局信息。 传输测量是通过使用弹道电子发射显微镜将电子注入这些结构中来实现的，从而可以表征电子散射随温度和能量的变化。 总之，这些组合数据将使人们能够更全面地了解各种材料系统中电子特性的降维。 更重要的是，将该领域的研究重点扩大到更多样化的分层材料阵列将增强我们对二维系统基础物理学的理解。 修改当前的理论，以涵盖更广泛的分层材料导致更强大的理论模型，设备的设计至关重要。