• Soler, Jose M.
• Amo-Ochoa, Pilar
• Ares, Pablo
• Palacios, Juan Jose
• Zamora, Felix
• Gomez-Herrero, Julio

Abstract

Molecular wires are essential components for future nanoscale electronics.<br/>However, the preparation of individual long conductive molecules is still a<br/>challenge. MMX metal–organic polymers are quasi-1D sequences of single<br/>halide atoms (X) bridging subunits with two metal ions (MM) connected by<br/>organic ligands. They are excellent electrical conductors as bulk macroscopic<br/>crystals and as nanoribbons. However, according to theoretical calculations,<br/>the electrical conductance found in the experiments should be even higher.<br/>Here, a novel and simple drop-casting procedure to isolate bundles of few to<br/>single MMX chains is demonstrated. Furthermore, an exponential dependence<br/>of the electrical resistance of one or two MMX chains as a function of<br/>their length that does not agree with predictions based on their theoretical<br/>band structure is reported. This dependence is attributed to strong Anderson<br/>localization originated by structural defects. Theoretical modeling confirms<br/>that the current is limited by structural defects, mainly vacancies of iodine<br/>atoms, through which the current is constrained to flow. Nevertheless, measurable<br/>electrical transport along distances beyond 250 nm surpasses that of<br/>all other molecular wires reported so far. This work places in perspective the<br/>role of defects in 1D wires and their importance for molecular electronics.

Topics

• impedance spectroscopy
• polymer
• experiment
• defect
• casting
• wire
• electrical conductivity
• band structure