二维稀土材料的可控制备及应用探索

Two-dimensional (2D) materials are a class of materials with atomic thickness. Due to the quantum confinement effect, they show unique properties compared with the traditional bulk materials. Rare earth elements with unique 4f electronic configuration own excellent optical, electrical and magnetic properties and can be the key materials for various fields, such as lighting, displaying, magnetic devices and detection. However, until now, the controlled fabrication of high-quality 2D rare earth materials has been rarely reported. This project intends to focus on this important class of materials, i. e. rare earth materials, and aims to achieve the controllable fabrication of their high-quality 2D materials, which will expand and enrich the 2D material family. The new properties of rare earth materials in the 2D limit will also be revealed. Liquid metal chemical vapor deposition (CVD) strategy will be employed for the controllable fabrication of high-quality 2D rare earth materials with adjustable layer number. The liquid metal owns ultra-smooth surface, excellent diffusibility and fluidity and its bulk with vacancies can embed heterogeneous atoms, which will facilitate the precise control of the segregation, reaction, nucleation, growth and other elementary steps in the CVD process. Based on the obtained 2D rare earth materials, their luminescence, electrical transport and magnetic properties can be fully explored, which will lighten the related applications. The project will lay a foundation for exploring the properties of 2D rare earth materials and their future applications in lighting, displaying, detection, field effect transistors and magnetic devices.

二维材料是一类具有原子级厚度的材料，由于量子限域效应，其较之传统块体材料会表现出独特的性质。稀土元素因为特殊的4f电子构型具有优异的光、电、磁学性质，是照明、显示、磁学器件和检测等领域的关键材料。然而，迄今为止，高质量的二维稀土材料的可控制备仍鲜有人报道。本项目拟聚焦稀土材料这一类重要材料，提出高质量二维稀土材料的可控制备方法，研究其在二维限域下的新性质，拓展和丰富二维材料家族。本项目拟采用液态金属化学气相沉积法（CVD）策略，利用液态金属体相有包埋异质原子的空位、表面超平滑、扩散性优异和可流动的特点，控制CVD过程中的析出、反应、成核和生长等基元步骤，制备层数可控的高质量二维稀土材料。基于所获得的二维稀土材料，探究其发光、电学输运和磁学等各项性质，实现在各种新型器件中的应用初探。该项目的开展将为二维稀土材料的性质探究和未来在照明、显示、检测、场效应晶体管和磁学器件等领域的应用奠定基础。

二维材料是一类具有原子级厚度的材料，由于量子限域效应，其较之传统块体材料会表现出独特的性质。稀土元素因为特殊的4f电子构型具有优异的光、电、磁学性质，是照明、显示、磁学器件和检测等领域的关键材料。然而，迄今为止，高质量的二维稀土材料的可控制备仍鲜有人报道。本项目聚焦稀土材料这一类重要材料，提出高质量二维稀土材料的可控制备方法，研究其在二维限域下的新性质，拓展和丰富二维材料家族，取得了一系列创新性成果。基于液态金属化学气相沉积方法，通过构筑“软硬酸碱”对，实现了具有特定晶面的稀土氧化物高质量二维单晶的普适性生长，并探索了其磁学性质；发展了一种基于稀土元素的双原子对策略，利用Ce-Pt，Pt-S之间的相互作用，获得了具有灵活可调层间距的稀土基二维材料“弹簧”，调控了其层数—性质依赖关系；设计合成了具有宽带隙、高稳定性和易于取代位点的二维无机框架材料（Ca5(PO4)3OH），通过引入比例可调的自转换稀土离子发光中心（Eu2+和Eu3+），成功实现了从绿色到橙色的多色发光。