Quantum interference features and thermoelectric properties of macrocyclic-single molecules: theoretical and modelling investigation

Abstract

The quantum interference effect on the thermoelectric properties of cycloparaphenylacetylene-based molecular junctions was investigated theoretically using a combination of density functional theory (DFT) methods, a tight binding (Hückel) model (TBHM) and quantum transport theory (QTT). Manipulating the unique conjugation function of these molecules not only creates a quantum interference (QI) but it is also a robust strategy for improving the thermoelectric properties of these molecules. QI controls the transport behaviour and decreases the electrical conductance (G) from 0.14 × 10⁻⁷ to 0.67 × 10⁻¹¹ S, as well as enhancing the Seebeck coefficient (S) from 14.4 to 294 μV K⁻¹, and promoting the electronic figure of merit (Z_elT) from 0.008 to 1.8, making these molecules promising candidates for thermoelectric applications.