Thermoelectric properties through a wire composed of isoprene molecules

Abstract

In this work, we study the electrical and thermoelectric properties through carbon bonds acting as nanowires derived from linear unsaturated organic molecules with a π conjugated system composed of isoprene molecules (NWIM) linked to leads. The study of electrical properties is conducted through the length of the NWIM and molecular couplings, and that of thermoelectric properties is conducted through a hemiterpenoid with a single isoprenic unit as the chemical scaffold. We approach the system by modeling it based on a tight-binding Hamiltonian model and solving it by using analytical means such as the renormalization process and Green’s functions. We obtain the transmission probability by utilizing the Fisher–Lee relationship. In the linear response approximation, by analyzing the electronic conductance (G), the thermal conductance (κ), the Seebeck coefficient (S), and the figure of merit (ZT), the molecular system clearly shows a behavior similar to that of a semiconductor material, obtaining a better thermoelectric performance with an asymmetric transmission probability at the edges of the band. Remarkably, by careful selection of the Fermi energy, the system plays an important role in the effectiveness of the ZT. These results offer a novel approach to molecular-based device designs, where the change in conductance due to the length effect in the NWIM can produce changes in the insulator–conductor states.