Interfacial Doping at Surfaces and in Low-Dimensional Materials

表面和低维材料中的界面掺杂

• 批准号: RGPIN-2018-06145
• 负责人: Kruse, Peter
• 金额: $ 1.75万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=656047
• 关键词: Interfacial; Doping; Surfaces; Low; Dimensional

The word ‘to dope' derives from the Dutch word ‘doop' meaning ‘thick dipping sauce', so ‘doopen' means ‘to dip'. In the context of electronic materials, it refers to introducing impurities (dopants) into or onto a material that lead to a change in its electronic properties. Such a change is easily detected, e.g. by measuring the change in resistance of a thin film or low-dimensional structure. So the absence or presence of the ‘dipping sauce', or dopant, can be determined quantitatively with great accuracy, e.g. for use in gas or liquid sensors. A challenge for such a sensor is how to remove the ‘dipping sauce' afterwards in order to reuse the device. We introduce the concept of molecular switches as chemical dopants for thin nanocarbon (or other two-dimensional material) films. These molecules can be switched between doping and non-doping states in the presence or absence of a particular analyte. They impart selectivity not only due to their change in doping behavior, but also by physically blocking other potential dopants in the analyte solution from interacting with the conductive film. In effect, they form a ‘dipping sauce' that can stay on, because it can be made to change flavor. Based on this concept, we have demonstrated disinfectant sensors for drinking water fabricated from carbon nanotube networks or pencil-drawn films coated in redox-switchable oligoanilines. The concept can also be applied to other analytes (pH, anions, cations, etc. in drinking water), but it becomes necessary to better understand these switchable dopants, and how they work. ******This proposal aims to build an understanding of the interactions of switchable dopant molecules with 2-dimensional materials such as graphene, molybdenum disulfide or percolation networks made of different grades of carbon nanotubes. In particular, there are five aspects of the molecule-substrate interaction that we will elucidate: (1) The role of the chemical identity of the substrate; (2) The role of substrate film topology (e.g. network vs. single crystal); (3) Application of an external electric field to balance out and quantify the molecular doping effect; (4) Electronic structure of the molecules, also considering steric aspects; (5) Nature of the tether of the molecules to the substrate film (non-covalent vs. covalent) and relation to chemical defects in the substrate. ******Our sensors have the potential to be more robust, simple and reliable than any other available technology. The disinfectant sensors are already on their way to commercialization for drinking water quality control, but we aim to develop and deploy anion, cation, pH, and disinfectant sensors for water quality control in municipal water supplies, on first nations reserves, surface waters near mines or agricultural land, etc., thus benefitting the health of all Canadians, and their environment. Our sensors can also find applications in healthcare, research, or process control.

“to dope”一词源自荷兰语“doop”，意思是“浓稠的蘸酱”，因此“doopen”的意思是“浸入”。在电子材料中，它指的是在电子材料中引入杂质（掺杂剂）。导致其电子特性变化的材料很容易检测到，例如通过测量薄膜或低维结构的电阻变化，因此“浸渍酱”或掺杂剂的存在与否。能可以高精度地定量确定，例如用于气体或液体传感器，这种传感器面临的挑战是如何去除“浸渍酱”以便重新使用该设备。这些分子可以在存在或不存在特定分析物的情况下在掺杂和非掺杂状态之间切换，它们不仅由于其掺杂行为的变化而具有选择性。物理阻挡分析物溶液中的其他潜在掺杂剂与导电膜相互作用，实际上，它们形成了一种可以保留的“蘸酱”，因为它可以改变味道。基于这个概念，我们有用于饮用水的消毒剂传感器。由碳纳米管网络或涂有可氧化还原的低聚苯胺的铅笔绘制薄膜制成。该概念也可应用于其他分析物（饮用水中的 pH、阴离子、阳离子等）。为了更好地理解这些可切换掺杂剂及其工作原理，该提案旨在了解可切换掺杂剂分子与石墨烯、二硫化钼或由不同材料制成的渗滤网络等二维材料的相互作用。特别是，我们将阐明分子与基底相互作用的五个方面：（1）基底化学特性的作用；（2）基底膜拓扑的作用。 （例如网络与单晶）；（3）应用外部电场来平衡和量化分子掺杂效应；（4）分子的电子结构，还考虑空间方面；分子与基材薄膜的关系（非共价与共价）以及与基材中化学缺陷的关系 ******我们的传感器比任何其他现有技术都更强大、更简单、更可靠。传感器已经开始商业化用于饮用水质控制，但我们的目标是开发和部署阴离子、阳离子、pH 和消毒剂传感器，用于市政供水、原住民保护区、矿山或农田附近的地表水等的水质控制，从而造福于人们的健康所有加拿大人及其环境。我们的传感器还可以在医疗保健、研究或过程控制中找到应用。