Thermally induced charge current through long molecules

TL;DR

This paper theoretically investigates how thermoelectric current through long molecular bridges depends on length, electron transmission, bias, and vibrations, revealing key factors influencing molecular thermoelectric behavior.

Contribution

It introduces a detailed theoretical analysis of length-dependent thermocurrent in long molecules, considering electron transmission and vibrational interactions, extending prior models.

Findings

Thermocurrent depends on the transmission lineshape in HOMO/LUMO channels.

Vibrational interactions significantly influence length-dependent thermocurrent.

Length and bias affect thermoelectric transport beyond linear response regimes.

Abstract

In this work we theoretically study steady state thermoelectric transport through a single-molecule junction with a long chain-like bridge. Electron transmission through the system is computed using a tight-binding model for the bridge. We analyze dependences of thermocurrent on the bridge length in unbiased and biased systems operating within and beyond linear response regime. It is shown that length-dependent thermocurrent is controlled by the lineshape of electron transmission in the interval corresponding to HOMO/LUMO transport channel. Also, it is demonstrated that electron interactions with molecular vibrations may significantly affect length-dependent thermocurrent.