Structure and composition of interfaces between 2D materials and dielectric substrates

二维材料与介电基板之间界面的结构和组成

• 批准号: 2433281
• 金额: --
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2433281
• 关键词: Structure; composition; interfaces; between; 2D

The rich and exciting electronic and mechanical properties of two-dimensional (2D) materials have inspired novel ideas for post-silicon nanoelectronics. Some of the most far-reaching of them concern the possible substitution of Si with 2D materials in modern field-effect transistors (FETs) and applications in next-generation memory and neuromorphic computing chips. Success of these applications relies on solving the materials problems related to defects at interfaces between 2D materials and gate dielectrics or metal electrodes. For example, the sandwich structure of memristive devices is usually composed of an insulating active layer (e.g., transition metal oxides (TMOs)), 2D material (graphene, MoS2) and top/bottom metal electrodes. This project will combine theoretical modelling of such interfaces with experimental investigations of their properties using hard x-ray photoelectron spectroscopy (HAXPES). Theoretical simulations of interfaces of 2D materials, such as MoS2 and WSe2, with SiO2, HfO2 and CaF2 insulating layers will be used to analyse the experimental HAXPES spectra of these systems and study the properties of point defects at interfaces. HAXPES measurements at DIAMOND and other facilities will help us to elucidate the effects of deposition and adsorbates on the chemical composition of interfaces. Theoretical calculations using both atomistic simulations and density functional theory calculations should allow us to identify interface defects as well as oxide defects near interfaces and relate them to reliability issues pertaining to FETs and mechanisms of resistive switching of oxides.

二维（2D）材料的丰富和令人兴奋的电子和机械性能激发了后硅纳米电子学的新想法。其中一些最深远的影响涉及在现代场效应晶体管（FET）中用2D材料替代Si的可能性以及在下一代存储器和神经形态计算芯片中的应用。这些应用的成功依赖于解决与2D材料和栅电极或金属电极之间的界面处的缺陷相关的材料问题。例如，忆阻器件的夹层结构通常由绝缘有源层（例如，过渡金属氧化物（TMO））、2D材料（石墨烯、MoS 2）和顶部/底部金属电极。该项目将把这种界面的联合收割机理论建模与利用硬X射线光电子能谱对其性质的实验研究结合起来。二维材料，如MoS 2和WSe 2，与SiO2，HfO 2和CaF 2绝缘层的界面的理论模拟将被用来分析这些系统的实验HAXPES谱，并研究界面处的点缺陷的性质。在DIAMOND和其他设施的HAXPES测量将帮助我们阐明沉积物和吸附物对界面化学组成的影响。使用原子模拟和密度泛函理论计算的理论计算应该使我们能够识别界面缺陷以及界面附近的氧化物缺陷，并将它们与FET的可靠性问题和氧化物的电阻开关机制有关。