Explorando propriedades de transporte elétrico e térmico em materiais à base de carbono para aplicações em eletrônica molecular: uma perspectiva computacional

Abstract

This study explores molecular devices in the field of molecular electronics, in which the possible applications such as organic LEDs, solar cells, sensors and other. Fullerene C60, a carbon molecule with a delocalized π system, has shown promise for molecular electronics applications. Using a computational approach combining Landauer-Büttiker scattering theory and Density Functional Theory (DFT) to investigate the structural, electronic, and thermal properties of moleculares systems. Seven molecular models were constructed, with fullerene acting as the electrode and aromatic molecules as conductors. Anthracene-cis, biphenyl, and pyrene stood out with electric currents of 2000 nA and electrical conductance ranging from 10-4 to 10-3 . The introduction of NO₂ and NH₂ groups in the junction device altered electric currents by ±500 nA and the Seebeck coefficients varied between 10-7 and 10-6 in both cases. It was observed that the number and arrangement of aromatic rings influenced the properties. The studied systems were consistent with other systems using gold or graphene electrodes, exhibiting behaviors similar to semiconductors and metals.