Theoretical investigation of thermoelectric properties of methyl blue-based molecular junctions

Abstract

Thermoelectric properties of a family of methyl blue-based molecular junctions were theoretically studied using a combination of density functional theory (DFT) methods, and quantum transport theory (QTT). Employing different numbers of amino groups not only proves itself as a powerful strategy for controlling the transport behaviour and lifting the transmission coefficient T(E) from 1.91 × 10⁻⁵ to 7.45 × 10⁻⁵ with increasing the amino groups from zero to four, but also it enhances the thermoelectric properties of these molecules, since it increases the Seebeck coefficient (S) from 106.8 to 202.4 μV K⁻¹ and the electronic figure of merit (Z_elT) has been raised from 0.15 to 0.35, making these molecules promising candidates for thermoelectric applications.