Band gap and electronic structure of 2D-systems, spinelectronics and ultra-hard materials studied with synchrotron-based soft X-ray Spectroscopy and Density Functional Theory

使用基于同步加速器的软 X 射线光谱和密度泛函理论研究二维系统、自旋电子学和超硬材料的带隙和电子结构

• 批准号: RGPIN-2015-05498
• 负责人: Moewes, Alexander
• 金额: $ 2.55万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=659941
• 关键词: Band; gap; electronic; structure; 2D

The outer and less strongly bound electrons of matter are responsible for most material properties including color, chemical-bonding capacity, hardness, magnetism, band gap, electronic structure, and catalytic activity to electrical and heat conductivity and even super-conductivity. Having the means to measure, model, and understand the outer electrons of a material gives us the key to understanding and tailoring important physical properties. This research will employ soft X-ray spectroscopy with synchrotron radiation to answer key questions concerning the structure of new materials in 3 areas of focus:***1. Ultra-hard materials for LED lighting applications: Hardness is inherently difficult to measure and therefore theoretical models can help to design materials that are harder than diamond (the hardest material known). We will further refine our model that relates the hardness of a material and its band gap, we will test the model experimentally with the goal to apply these materials in LED lighting applications. ******2. Spinelectronic materials for new storage devices and high performance computing:***We will find new suitable ferromagnetic semiconductors for applications that use the electron spin and charge to store information. If realized on a large scale, spintronics will revolutionize computing capabilities by allowing faster processing speed and higher storage density.******3. Two dimensional (2D) materials: The growth of graphene - a 2D single isolated plane of graphite - and its integration in current silicon-based nanotechnology is facing several challenges, one having no band gap which is needed for semiconductor device applications. A 2D semiconductor would be extremely desirable for nanoscale device applications as well as supercapacitors and photovoltaic devices. Our work aims to: i) alter the properties of graphene to create a band gap and ii) develop another 2D semiconducting material such as the graphene analogue "silicene", in which the carbon atoms are replaced by silicon. Band structure and band gap are predicted to depend on the number of stacked layers, stacking sequence, and electric fields across the graphite layers. Other important questions include identification of a suitable substrate on which silicene could maintain a band gap or the correct layer structure.******Overall, the comparison of synchrotron measurements with state-of-the-art calculations will provide very detailed insight and facilitate the design of new materials with tailored electronic, optical, magnetic, and chemical properties for use in industrial, medical and electronic contexts.**

物质的外层电子和弱束缚电子决定了大多数材料特性，包括颜色、化学键合能力、硬度、磁性、带隙、电子结构以及对导电性和导热性甚至超导性的催化活性。拥有测量、建模和理解材料外层电子的方法，为我们提供了理解和定制重要物理特性的关键。这项研究将采用软 X 射线光谱和同步加速器辐射来回答有关 3 个重点领域的新材料结构的关键问题：***1。 用于 LED 照明应用的超硬材料：硬度本质上很难测量，因此理论模型可以帮助设计比金刚石（已知最硬的材料）更硬的材料。我们将进一步完善我们的模型，将材料的硬度与其带隙联系起来，我们将对模型进行实验测试，目标是将这些材料应用于 LED 照明应用。 ******2.用于新型存储设备和高性能计算的自旋电子材料：***我们将为使用电子自旋和电荷存储信息的应用找到合适的新铁磁半导体。如果大规模实现，自旋电子学将通过更快的处理速度和更高的存储密度彻底改变计算能力。******3。二维 (2D) 材料：石墨烯（一种石墨的 2D 单隔离平面）的生长及其在当前硅基纳米技术中的集成面临着多项挑战，其中之一不具备半导体器件应用所需的带隙。二维半导体对于纳米级器件应用以及超级电容器和光伏器件来说是非常理想的。我们的工作目标是：i）改变石墨烯的特性以产生带隙，ii）开发另一种二维半导体材料，例如石墨烯类似物“硅烯”，其中碳原子被硅取代。预计能带结构和带隙取决于堆叠层数、堆叠顺序和石墨层上的电场。其他重要问题包括确定硅烯可以在其上保持带隙或正确的层结构的合适基底。******总的来说，同步加速器测量与最先进的计算的比较将提供非常详细的见解并促进具有定制电子、光学、磁性和化学特性的新材料的设计，用于工业、医疗和电子环境。**