title: Revealing the Nature of Molecule-Electrode Contact in Tunneling Junctions Using Raw Data Heat Maps.
abstract: Mechanistic understanding of charge transport through molecular tunnel junctions requires reproducible and statistically relevant data sets. This challenge has been overcome by development of large area junctions, especially those based on liquid-metal physi-sorbed top-electrodes, such as eutectic gallium-indium. A challenge with these junctions, however, is an inability to diagnose the quality of contact between the top-electrode and the SAMs. Since tunneling currents are dependent on the distance between the two electrodes, we demonstrate that by analyzing all raw unfitted data derived from a measurement using heat-maps, one can deduce the quality of contact and other minor bias-dependent fluctuations in the charge transport behavior. We demonstrate that the use of 3D plots would be challenging to interpret, but adoption of heat maps clearly captures details on junction quality irrespective of the total size of the data set or molecules used. We propose representation of raw data, rather than reliance on statistics, as proof of quality junctions.
authors.affiliation: Department of Materials Science and Engineering, Iowa State University , 2220 Hoover Hall, Ames, Iowa 50011 United States.
authors.forename: Jacob
authors.initials: J
authors.lastname: Sporrer
authors.affiliation: Department of Materials Science and Engineering, Iowa State University , 2220 Hoover Hall, Ames, Iowa 50011 United States.|Micro-electronic Research Center, Iowa State University , 133 Applied Sciences Complex I, 1925 Scholl Road, Ames, Iowa 50011 United States.
authors.forename: Jiahao
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Materials Science and Engineering, Iowa State University , 2220 Hoover Hall, Ames, Iowa 50011 United States.
authors.forename: Zhengjia
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Materials Science and Engineering, Iowa State University , 2220 Hoover Hall, Ames, Iowa 50011 United States.|Micro-electronic Research Center, Iowa State University , 133 Applied Sciences Complex I, 1925 Scholl Road, Ames, Iowa 50011 United States.|Biopolymer and Bio-composites Research Team, Center for Bioplastics and Bio-composites, Iowa State University , 1041 Food Sciences Building, Ames, Iowa 50011 United States.
authors.forename: Martin M
authors.initials: MM
authors.lastname: Thuo
keywords: charge tunneling; data analysis; junction quality; large area junction; molecular electronics