Room-temperature negative differential resistance in nanoscale molecular junctions

Molecular devices are reported utilizing active self-assembled monolayers containing the nitroamine ${\text{[2}}^{\prime }-\mathrm{amino-4}{\text{,4}}^{\prime }-\mathrm{di(ethynylphenyl)}{\text{-5}}^{\prime }-\mathrm{nitro-1-benzenethiolate}]$ or the nitro compound ${\text{[4,4}}^{\prime }-\mathrm{di(ethynylphenyl)}{\text{-2}}^{\prime }-\mathrm{nitro-1-benzenethiolate}]$ as the active components. Both of these compounds have active redox centers. Current–voltage measurements of the devices exhibited negative differential resistance at room temperature and an on–off peak-to-valley ratio in excess of 1000:1 at low temperature.