(Invited) Towards a Perfect Junction: Effect of Smoothening Electrodes on Tunneling Behaviors across Large Area Molecular Junctions

• Main Authors: Chen, Jiahao, Kundu, Souvik, Du, Chuasen, Kadoma, Atte, Giroux, Thomas, Thuo, Martin
• Format: Conference Proceeding
• Language: English
• ISSN: 1938-5862; 1938-6737; 1938-6737; 1938-5862
• DOI: 10.1149/08603.0079ecst

Eutectic gallium indium (EGaIn), as top electrode for self-assembled monolayers (SAMs) based tunneling junction, has recently received heightened attentions, in part, due to its ease of fabrication, high-yield working junctions, and reproducibility. Despite these advances, effect of sub-nanometer roughness inhibits delineation of second-order effects on tunneling characteristics that are inherent in the molecules or molecular assemblies. Some other effects, such as molecule/electrode interactions and field-dependent intra-molecular van der Waals interactions, can lead to new approaches of tuning charge transport properties. One challenge, however, is that junctions have inherent defects that can significantly skew interpretation of obtained results. Addition challenge is the decoupling of subtle molecular effects from vast number of measurements that usually give large distributions. To mitigate these challenges, we deployed a three-pronged approach entailing; i) tuning roughness of the bottom electrode at the angstrom scale, ii) polishing of the top-electrode, and iii) deploying statistical analysis to uncover interface effects. In this paper, the effect of these modifications on SAM and associated charge transport behavior will be discussed.