Thermovoltaic Effects of van der Waals Heterojunctions based on Inert Conductor/Solution Interfaces

TL;DR

This paper investigates the thermovoltaic effect in van der Waals heterojunctions formed at inert conductor/solution interfaces, revealing how differences in work function and surface states generate voltage and current through physical adsorption and P-N junction formation.

Contribution

It introduces a novel understanding of thermovoltaic effects arising from inert conductor/solution interfaces and the formation of van der Waals heterojunctions, expanding the scope of thermoelectric research.

Findings

Inert conductor/solution interfaces form van der Waals heterojunctions.

Differences in work function and surface states create a built-in electric field.

The thermovoltaic effect produces measurable voltage and current changes.

Abstract

It is found that if the inert conductor P has a larger electron work function $\phi$ and surface state function G than the inert conductor N, the inert conductor P and the inert conductor N are isolated by a separator and then immersed in the solution S (abbreviation: inert conductorP$\mid$solutionS$\mid$inert conductorN, or as P$\mid$S$\mid$N). Excluding the electrochemical reaction and thermoelectric effect of P$\mid$S$\mid$N, etc., it is measured that the voltage between the two conductors after the open circuit continues to increase to a certain stable maximum value. Then, the current after the closed-circuit continues to decrease to a certain stable minimum value. Analysis of the structure and properties of P$\mid$S$\mid$N shows that the inert conductor/solution interface relies on physical adsorption to construct van der Waals heterojunctions and that two van der Waals heterojunctions of different potentials form a P-N junction for P$\mid$S$\mid$N. The inert conductors P and N have different potentials. This electric field energy is expressed in the outer circuit when the circuit is open, due to the joint action of the electron work function $\phi$ and the surface state function G, P$\mid$S$\mid$N generates a larger built-in electric field and obtains a larger voltage. When the circuit is closed, P$\mid$S$\mid$N only has the effect of the surface state function G, which produces a smaller built-in electric field, results in a smaller voltage and current. This Thermoelectric conversion phenomenon is called the thermovoltaic effect.