Influence of Central-Metallic Atoms of Molecular Junction on Electrical and Thermal Transport

Abstract

Molecular structures of a series of metal-complexes molecules of bipyrimdine have interesting features in various applications such as industrial and scientific. The transition through metal complexes at molecular structures has a significant role in the metal-bridges interactions. Hence, the bipyrimdine's complex molecules were used to show the effect of the metal atoms on the electronics, electrical, and thermoelectric properties and to identify the π-conjugated system in all attempts before/ or after replaced one carbon with nitrogen atoms in one or two the pyridine rings.SIESTA code, and GOLLUM code programs were used in our calculations. The results showed that the energy gap decreased significantly with the type of metal atoms, which appear in electronic applications at various LUMO-HOMO energy gaps. The electrical and thermal results have confirmed the effect of metal-complexes center atoms in the transmission and Seebeck coefficients.From the position of the Fermi energy (E-EF=0 eV), the conductance and the thermopower values are determined, and thus the specificity figure of merit ZTe was computed. Therefore, we found the ZTe be a high value for bipyridine molecule about 1.7, which is several order of magnitude higher than of the set molecules. Whereas a low value of ZTe for Cr-metal- molecule.