Electric Field Regulated High Thermal Rectification Ratio using Ferrocenyl Terminated Molecular Junction

Conventional silicon-based electronic devices have electron conductance rectification ratios greater than . This magnitude was achieved in molecular electric diode composed of ferrocenyl (Fc) terminated self-assembly monolayers (SAMs) developed by the Nijhuis group [<i>Nature Nanotech 12, 797–803 (2017)</i>]. Perhaps surprisingly, the largest thermal rectification ratio reported so far in materials and devices is at the magnitude of near 1. Applying the same electrostatic attraction mechanism seen by the Nijhuis, we have found in atomistic simulations that ferrocenyl terminated molecular junctions can also achieve high thermal rectification ratio. In the forward bias case, the top electrode is negatively charged, the Fc group is positively charged, and the strong electrostatic force drag the Fc group closer to the top electrode and thereby enhances thermal conductance. In the backward bias case, the Fc group is charge neutral, and the electrostatic force between the Fc groups and the top electrode is weak and thereby reduces thermal conductance. We will report the distance between the two electrodes, the partial charge on the Fc group, the electric field magnitude, and the number of SAM molecules affecting heat transfer. The implications of this work for developing next-generation phononic devices will also be discussed.<br/><br/><br/>References:<br/>Wei <i>et al.</i>, Thermal Transport through Polymer-Linked Gold Nanoparticles, <i>J. Phys. Chem. C 2022, 126, 43, 18511–18519</i>. https://doi.org/10.1021/acs.jpcc.2c05816<br/>Wei and Hernandez, Heat Transfer Enhancement in Tree-Structured Polymer Linked Gold Nanoparticle Networks, <i>in preparation</i>.