Estudo do transporte eletrônico em nanoestruturas baseadas em carotenoides e tétrades com fulereno C60

Abstract

In this work it is presented a theoretical study on the electronic structure of a fullerene molecule (C60) with junctions in four terminals based on groups electron donors. tetrathiafulvalene (TTF) – and groups acceptors of electrons – fenilpropanodinilla (FPP) and molecular devices based on Carotenoid derivatives. The transport mechanism investigated for the carotenoids derivatives were utilized for better understanding of Fowler-Nordheim (FN) and Millikan-Lauritsen (ML) plots for the systems based in fullerene C60. In all cases it was possible to confirm that the Millikan- Lauritsen (ML) analysis empirical is also sufficient to describe all aspects the transition voltage spectroscopy (TVS). To study this class of systems, optimize the geometry systematically and observe the electronic transfer calculated by Hartree-Fock and Density Functional Theory (DFT). The results show through a detailed analysis of the molecular charge rearrangement due to an external electric field shows that the charge transport is directly on to the type of junction that this system is submitted of form that the applied voltage suffices to create a saturation potential in the systems in study: fullerene C60 with three terminals of tetrathiafulvalene and one terminal of fenilpropanodinilla (C60-(TTF)3-FPP); fullerene C60 with four terminals of fenilpropanodinilla (C60-(FPP)4). The particularity observed in C60-(FPP)4 is the disposal of the structure to operate with rectifying character for the electronic transport in the presence of orthogonal electric field to terminal data. The results show that we have a Molecular rectifier that works as a macroscopic rectifier.