Scanning Tunneling Microscopy of Covalent Organic Frameworks

Summer 2016

Patrick Forrester : Physics

Mentor: Michael F. Crommie

In the past ten years, scientific interest has grown in the field of two dimensional self-assembled molecular structures because of their promise for flexible nanoscale electronic applications including single molecule sensing, improved photovoltaics, and organic light-emitting diodes. Covalent Organic Frameworks (COFs) are strong candidates for these applications by virtue of their mechanical and thermal stability, transparency to visible light, and ease of large scale production, which could potentially revolutionize electronics and alternative energy. Currently, two-dimensional COF synthesis is not well understood and relies heavily on trial and error, and there is little microscopy data available to resolve the structure of these materials at the atomic level. My research project will use scanning tunneling microscopy, which allows for atomic-scale resolution, to test candidate COF precursors in order to determine if in situ polymerization of ordered structures occurs on various metallic and insulating substrates using thermal activation. I will also perform scanning tunneling spectroscopy to measure the electronic properties of these COFs such as band gap, orbital overlap, and impurity states, all of which are essential measurements for determining device-based application viability of COFs.

I would like to thank SURF L&S and the Pergo Foundation for providing me with the financial freedom to pursue this project over the summer. I would also like to thank my adviser, Professor Michael Crommie, as well as Hsin-Zon Tsai, Daniel Rizzo, and Justin Lopez for their support and guidance. Without their help, I would be unable to conduct this research.