Heat dissipation and its relation to molecular orbital energies in single-molecule junctions

TL;DR

This paper theoretically investigates heat dissipation in single-molecule junctions, revealing how it depends on electronic structure, bias polarity, and transmission spectra, with implications for identifying dominant energy levels in transport.

Contribution

It introduces a toy model linking heat dissipation to transmission spectra and validates findings with C60 molecular junctions, advancing understanding of heat flow in molecular electronics.

Findings

Heat dissipation varies with bias polarity and energy level positions.

Heat is not equally dissipated in both electrodes.

Results can identify energy levels dominating transport.

Abstract

We present a theoretical study of the heat dissipation in single-molecule junctions. In order to investigate the heat dissipation in the electrodes and the relationship between the transmission spectra and the electronic structures, we consider a toy model that in which electrodes linked by a two-level molecular bridge. By using of the Landauer approach, we show how heat dissipation in the electrodes of a molecular junction is related to its transmission characteristics. We show that in general heat is not equally dissipated in the left and right electrodes of the junction and it depends on the bias polarity and the positions of molecule's energy levels with respect to the Fermi level. Also, we exploit the C$_{60}$ molecule as a junction and the results show a good agreement with the toy model. Our results for the heat dissipation are remarkable in the sense that they can be used to detect which energy levels of a junction are dominated in the transport process.