Student: Atte Kadoma, Undergraduate Student in Materials Engineering, Iowa State University
Research Mentor: Dr. Martin Thuo
Effect of Surface Roughness on the odd-even limit in charge transport characteristics of large-area tunneling junctions
Self-assembled monolayers (SAMs) are ordered structures formed by spontaneous chemisorption of organic molecules to a surface. For their tunability and sensitivity, SAMs provide facile means to tailor interfacial surface properties. Surface roughness, quantified through root-mean-squared roughness (Rrms), has been shown to impact the formation of SAMs on metallic substrates.
Previously, we studied the effect of surface roughness on interfacial wetting properties of SAMs, where the contact angle of SAMs showed a zigzag trend as the chain length increases (odd-even effect). We determined that Rrms, the most commonly used parameter, is insufficient to describe all the SAM interfacial property changes caused by surface roughness. Thus, to further investigate the effect of roughness it is imperative to establish an accurate parameter to quantify it. In this study, we revisit this problem using a different investigation method, charge tunneling.