新型二维硫化铬的化学气相沉积法制备及其电、磁性能探索

信息社会与光、电、磁材料息息相关。石墨烯、MoS2等已有二维材料在光、电等方面具有优异性能，各自也存在优缺点；最近研究表明二维Cr2Ge2Te6和CrI3具有新颖磁性，然而具有本征磁性的二维材料还很缺乏。有限的理论研究表明二维CrS2具有优异光、电、磁性能，但实验研究鲜有报道。在申请人前期研究基础上，本项目研究二维CrS2的化学气相沉积法制备技术及探索其基本电、磁性能。将重点研究衬底表面拓扑结构和化学组分对合成二维CrS2的影响，进而揭示影响其成核生长的关键因素；结合理论研究，实验上重点研究在外加磁场下二维CrS2的相结构和层数对其能带结构、载流子输运、铁磁相转变等基本电、磁性能的影响。通过本项目研究，揭示控制二维CrS2成核生长的关键因素，建立可控制备技术；揭示二维CrS2的相结构和层数与其能带结构、载流子输运、铁磁相转变等之间的内在关联性，为认识具有潜在重要性的CrS2提供基础数据。

Our modern information society relies on the development of optical, electronic, and magnetic materials. With their own advantages and disadvantages, typical two-dimensional (2D) materials such as graphene and MoS2 have unique optical and electronic properties. However, of all the types of condensed-matter behavior that have been observed in 2D materials, intrinsic magnetism has been notably absent. As recently published in Nature, clear signatures of ferromagnetism in two chromium-based 2D materials, i.e. mechanically exfoliated Cr2Ge2Te6 and CrI3, have been observed and unexpected new effects have been uncovered. Furthermore, very limited theoretical studies have shown that 2D CrS2 not only has unique optical and electronic properties, but exhibits outstanding magnetic properties. However, there is few report on experimental study of 2D CrS2 so far. Here, on the basis of our preliminary study of 2D CrS2, we will develop methods for 2D CrS2 synthesis based on chemical vapor deposition and explore its fundamental electronic and magnetic properties. We will systematically investigate the influence of topological structure and chemical component of substrates on the synthesis of 2D CrS2. By combining theoretical study, we will experimentally study its fundamental electronic and magnetic properties of 2D CrS2 as functions of the phase and the layer number of CrS2 under applied magnetic field. Based on our study, we aim to reveal the dominant factors which control the nucleation and growth of 2D CrS2 and establish appropriate protocols for the fabrication of 2D CrS2, and to elucidate the relationships between the phase and the layer number of 2D CrS2 and its electronic and magnetic properties such as energy band structure, carrier transport, and ferromegnetism. Our study will help us to comprehensively understand how to experimentally create 2D CrS2 and the fundamental electronic and magnetic properties of 2D CrS2. Combined with their rich electronics and optics, the emergence of magnetism in chromium-based 2D materials, if possible, could open up numerous opportunities for 2D magnetic, magnetoelectric, and magneto-optic applications.