Multipeak negative-differential-resistance molecular device

The development of a reliable metal-Fe based molecule-metal system with measured negative-differential-resistance (NDR), was investigated. The Fe-based compound retains a structure, resulting in a high-charge-density region on the Fe moiety and low charge density over the rest of the molecule. Gaussian density functional theory (DFT) calculations of unbound compound were performed. Electrical measurements were performed using a modified vertical methodology. An electrode was constructed on a silicon wafer that was covered with a thermal oxide layer by the evaporation of a 120-nm layer of gold on a 50-nm Ti adhesion layer. Multiple NDER peaks from the Pd and Au coupling were observed in the molecular transport data. These peaks show that both redox and resonance transport processes take place during the electron-transfer process.