Nanoscale Control over Surface Functionalization by Molecular Layer Deposition

在化学系大分子、超分子和纳米化学(MSN)计划的支持下，斯坦福大学的Stacey Bent教授和她的研究小组正在开发新的化学方法，用于在表面沉积一层材料的分子层(分子层沉积(MLD))。这些层是纳米大小(十亿分之一米)，并在非常薄的薄膜中包含有机分子。表面的有机薄膜很重要，因为它们提供了调整材料电子、化学和机械性能的方法，应用范围从纳米电子到生物医学设备再到催化。该研究项目研究了将这些层添加到表面以及由此产生的有机薄膜的基本过程。从这项工作中获得的基本认识有助于介绍一种新的工具包，用于将具有有用和可调特性的薄膜附着到固体材料上。Bent团队为研究生和本科生研究人员提供指导和培训。该团队在一个多样化、多学科的环境中接待高中教师。STEM本科生有机会通过本特教授帮助发起的暑期实习计划在与能源相关的小型公司工作。该项目通过在两个主要方向上扩展MLD技术，为在固体表面控制合成功能薄膜贡献了新的方法。这项研究探索了基于溶液的方法可以通过在表面使用纳米厚的液体薄膜来实现有机MLD的新合成策略的方法。这些薄膜模拟了表面上的溶剂效应。该团队扩展了MLD方法，以创造新颖的混合表面组件，包括基于金属硫化物和金属氮化物的混合材料。薄膜的合成与阐明MLD机制以及微观和宏观薄膜性质的表征研究紧密结合在一起。实验和理论方法被用来揭示诸如反应程度、膜结构、长程有序的存在、链取向、膜的稳定性以及界面组装中的光学和电学性质等信息。这些研究旨在回答关于MLD的生长机制和薄膜结构与界面性质之间的关系的基本问题。总而言之，这项研究可能会导致为广泛的系统创建接口功能的新方法。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

With support from the Macromolecular, Supramolecular and Nanochemistry (MSN) Program in the Division of Chemistry, Professor Stacey Bent and her research group at Stanford University are developing new chemistries for carrying out processes that deposit a molecular layer of material on a surface (molecular layer deposition (MLD)). These layers are nanometer-sized (one billionth of a meter) and contain organic molecules in a very thin film. Organic thin films on surfaces are important because they provide ways to tune the electronic, chemical and mechanical properties of materials, with applications ranging from nanoelectronics to biomedical devices to catalysis. The research program studies the fundamental process by which the layers are added to the surface as well as the resulting organic films. The fundamental understanding gained from this work helps introduce a new tool-kit for attaching thin films with useful and tunable properties to solid materials. The Bent group provides mentorship and training to graduate students and undergraduate researchers. The team hosts high school teachers in a diverse, multidisciplinary environment. STEM undergraduates have the opportunity to work in small, energy-related companies through a summer internship program that Professor Bent helped initiate.The project contributes new methods for the controlled synthesis of functional thin films at solid surfaces by expanding the MLD technique in two principal directions. The research explores ways in which solution-based approaches can inform new synthetic strategies for organic MLD with the use of nanometer-thick films of liquids at the surface. These films mimic solvent effects on surfaces. The team expands MLD approaches to create novel, hybrid surface assemblies, including hybrid materials based on metal sulfides and metal nitrides. The film synthesis is closely integrated with characterization studies that elucidate MLD mechanisms and both microscopic and macroscopic film properties. Experimental and theoretical approaches are undertaken to uncover information such as the extent of reaction, film structure, the presence of long-range order, chain orientation, film stability, and optical and electrical properties in the interfacial assemblies. The studies aim to answer fundamental questions about growth mechanisms and the relationship between film structure and interface properties in MLD. Taken together, the research may lead to new approaches to create interfacial functionality for a wide range of systems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.