低维材料杂质和缺陷的理论研究和应用

发布时间：2018-02-26 20:06

本文关键词： 单层半导体材料的杂质和缺陷缺陷电子结构缺陷与催化　出处：《华东师范大学》2015年硕士论文　论文类型：学位论文

【摘要】：1959年 Richard Feynman以"There's Plenty of Room at the Bottom"为演讲题目,带领科学家进入一个新的物理领域：真实观测到单个原子,以及按我们的设想排列原子。20年之后,扫描电镜(STM)和原子力显微镜(AFM)的发明应用,使得调控单量子成为可能。目前实验上单量子自旋系统,如捕获离子、单分子、量子点、超导比特,是实现量子信息处理和自旋磁性数据存储的重要载体。较大的磁各向异性能(Magnetic anisotropic energy, MAE)是单量子自旋数据存储的基础,也是传统横向磁性数据存储的重要所在。云存储和大数据时代,迫切需要更高密度存储器,而单量子自旋有望成为最小存储单元,这使得调控单量子自旋成为二十一世纪信息科技领域的一大挑战。同时,低维材料,如石墨烯和单层MoS2,在氧还原反应(Oxygen Reduction Reaction, ORR)、析氢反应(Hydrogen Revolution Reaction, HER)等能源制备中得到深入研究,相比于纯净材料催化性能低劣,通过元素掺杂可以有效提高催化性能,其微观机理尚待研究。通过第一性原理计算,我们分别模拟了单个磁性原子吸附在单层MoS2表面和基于C80内嵌金属富勒烯的单量子自旋结构,并结合自旋-轨道耦合(Spin-orbit coupling, SOC)和分子轨道理论解释了MAE的起因,探究了Jahn-Teller效应对MAE的调控机制。此外,基于实验和理论计算,我们探究了共掺杂和缺陷协同作用显著提高石墨烯HER催化性能的微观机理。具体内容如下：第一章,阐述了高密度存储,及单量子自旋系统的研究进展；第二章,介绍了磁性存储的关键因子MAE的物理知识及第一性原理计算方法,Jahn-Teller效应、分子轨道理论概念；第三章,以单个磁性原子吸附在单层MoS2表面为研究体系,推导了单量子MAE的计算公式,依据第一性原理计算和分子轨道理论,提出了基于Jahn-Teller效应的MAE调控方法；第四章,设计了基于C80内嵌富勒烯的单分子磁体存储单元,计算了其磁学属性,并解析了MAE的起源；第五章,探究了原子共掺杂和晶格缺陷协同作用对提高石墨烯HER催化性能的机理；第六章,总结了本文涉及的单自旋量子结构设计要点和调控技术,及低维材料中掺杂和晶格缺陷的协同催化作用。
[Abstract]:In 1959, Richard Feynman in "There's Plenty of Room at the Bottom" as the topic, leading scientists to enter into a new field of Physics: the real observed single atoms, and then according to our assumption of the arrangement of atoms in.20, scanning electron microscopy (STM) and atomic force microscopy (AFM) of the invention, the control of single quantum becomes possible. The single quantum spin systems, such as ion capture, single molecule, quantum dots, superconducting qubits, is an important carrier to realize quantum information processing and data storage. The spin magnetic anisotropy can be larger (Magnetic anisotropic energy, MAE) is the basis of single quantum spin data storage, which is also important the traditional transverse magnetic data storage. The era of cloud storage and large data, an urgent need for more high density memory, while the single quantum spin is expected to become the minimum storage unit, which makes the regulation of single quantum spin Become a great challenge in the field of information technology in twenty-first Century. At the same time, low dimensional materials, such as graphene and MoS2 monolayer, during the oxygen reduction reaction (Oxygen Reduction Reaction, ORR), the hydrogen evolution reaction (Hydrogen Revolution Reaction, HER) to study the energy obtained in the preparation of pure material compared to the catalytic performance of the inferior by element doping can effectively improve the catalytic performance and its mechanism remains to be investigated by first principle calculations, we simulate a single magnetic atom adsorbed on the surface of MoS2 monolayer and single quantum spin structure based on C80 metallofullerenes, combined with spin orbit coupling (Spin-orbit, coupling, SOC) and the molecular orbital theory explains the MAE the reason, explores the regulation mechanism of Jahn-Teller effect on MAE. In addition, based on the experimental and theoretical calculation, we explored the synergistic effect of CO doping and defects increase graphene The microscopic mechanism of the catalytic performance of HER. The specific contents are as follows: the first chapter expounds the research progress of high density storage, and single quantum spin systems; the second chapter introduces the calculation method, the knowledge of the physics of key factor MAE magnetic storage and the first principle of Jahn-Teller effect, divided the concept of sub orbital theory; the third chapter, with a single the magnetic atom adsorbed on the surface of MoS2 monolayer system, derived the calculation formula of single quantum MAE, based on the first principle calculation and the molecular orbital theory, proposed the MAE control method based on Jahn-Teller effect; the fourth chapter, the design of single molecule magnet storage unit based on embedded C80 fullerene, its magnetic properties were calculated, and analysis the origin of MAE; the fifth chapter explores the atom doped and lattice defects in a synergistic effect on the mechanism of improving the catalytic performance of graphene HER; the sixth chapter, this paper summarizes the related single Design points of spin quantum structure and control technology, catalysis and lattice defects and doping in low dimensional materials.

【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN304

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