Materiales carbonáceos para el estudio del transporte de carga en hilos moleculares y desarrollo de puntos cuánticos : transporte de carga en uniones moleculares grafito-molécula-oro.

Abstract

This work presents a detailed study of the conductance and charge transport mechanism in the molecular junction composed of graphite-4,4' biphenyl dithiol-gold. Throughout the research, current peaks were identified when applying voltages in the range of 750 mV to -750 mV. One of the most significant findings was the observation of current rectification behavior for voltage values exceeding ±450 mV, suggesting the presence of asymmetry in the charge transport. Additionally, the molecular geometry of the junction was deduced, and it was concluded that the primary charge transport mechanism is coherent tunneling, meaning that electrons pass through the potential barrier without losing their phase. However, it was observed that for voltages between -600 mV and 600 mV, charge transport is non-resonant, implying no optimal coupling between the energy levels of the molecule and the electrodes. In contrast, for voltages exceeding |750| mV, transport becomes resonant, indicating better coupling. These results highlight the potential of this molecular junction for applications in the field of Molecular Electronics, particularly in the development of devices such as rectifying diodes and logic gates. This opens up new technological possibilities for the design of circuits at the molecular level.