二维面内异质结电子和磁性界面效应的理论研究

任何器件都离不开界面问题，对基于二维异质结材料的纳米器件更是如此。二维异质结纳米器件的快速发展，亟需相应异质结材料和器件的基础物理支持。目前，二维面内异质结理论研究集中于简单界面情形，而实验上大部分晶格失配的异质结，界面区域往往不可避免的存在缺陷或部分重叠。理论模型和实验结构的差异，导致理论结果不足以完整理解器件界面效应。基于此，本项目拟以晶格失配的二维面内异质结为研究对象，搭建与实验器件更贴近的二维复合界面异质结模型。建立经典静电学偶极子模型，探索复杂界面下的能带排列；结合第一性原理分子动力学方法，探索复合界面下载流子动力学界面量子效应；讨论二维面内磁性异质结中磁矩、磁序和居里温度等磁性质的界面效应。通过本项目研究，加深对二维面内异质结中能带排列、载流子动力学和磁性质的界面量子效应的理解，为光电纳米器件设计提供切实的理论支持。

Interface is important in device design, especially for devices based on two dimensional (2D) heterojunctions. It is known that the fully understanding of basic physics is crucial for the measure and design of 2D nano-devices. By now, theoretical studies on 2D lateral heterojunctions focused on those with simple interface. However, in experiment, the defects or overlapped region are inevitable for 2D lateral heterojunctions with large lattice mismatch. Therefore, this kind of difference makes it hard in understanding experimental measurements and interfacial effects in devices. Based on this question, in this work, we investigate the interfacial effects in 2D mismatched lateral heterojunctions. We will construct the interface models for 2D lateral heterostructures with the consideration of experimental measurements, modify the electrostatic dipole model and investigate the band offsets. Combine the first principle and molecular dynamic methods, we will study the interfacial effects on the carrier’s behavior when crossing the complex interfaces. For the 2D magnetic lateral heterojunctions, meanwhile, we will investigate the interfacial effects on the magnetic moments, magnetic phase, the Curie temperature and anisotropy. The goal of this project is trying to understand the quantum effects result from the complex interfaces, provide the theoretical support on future design of 2D heterostructure materials based photoelectric nano-devices.