# Length-dependent Seebeck effect in single-molecule junctions beyond linear response regime

## TL;DR

This paper theoretically investigates how the nonlinear Seebeck effect in single-molecule junctions depends on bridge length, revealing that thermovoltage and thermopower increase with length and are influenced by electrode coupling and terminal site properties.

## Contribution

It introduces a theoretical analysis of length-dependent nonlinear Seebeck effects in single-molecule junctions beyond linear response, considering bridge-electrode interactions.

## Key findings

- Thermovoltage $V_{th}$ increases with bridge length.
- Differential thermopower $S$ grows as the bridge lengthens.
- Bridge-electrode coupling affects the length dependence of $V_{th}$ and $S$.

## Abstract

In the present work we theoretically study characteristics of nonlinear Seebeck effect in a single-molecule junction with chain-like bridge of an arbitrary length. We have employed tight-binding models to compute electron transmission trough the system. We concentrate on analysis of dependences of thermovoltage $V_{th} $ and differential thermopower $ S $ on the bridge length. It is shown that $ V_{th} $ becomes stronger and $ S $ grows as the bridge lengthens. We discuss the effects of the bridge coupling to the electrodes and of specific characteristics of terminal sites on the bridge on the length-dependent $ V_{th} $ and $ S $ which appear when the system operates beyond linear response regime.