Nanoscale Control over Surface Functionalization by Molecular Layer Deposition

点击翻译按钮获取中文摘要

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.