Does the Seebeck coefficient of a single-molecule junction depend on the junction configuration?

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388955%3A_____%2F21%3A00544961" target="_blank" >RIV/61388955:_____/21:00544961 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68378271:_____/21:00580138

Výsledek na webu

<a href="http://hdl.handle.net/11104/0321747" target="_blank" >http://hdl.handle.net/11104/0321747</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/d1ta05324h" target="_blank" >10.1039/d1ta05324h</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Does the Seebeck coefficient of a single-molecule junction depend on the junction configuration?

Popis výsledku v původním jazyce

A new experimental method for the simultaneous determination of the electric and thermoelectric properties of metal-molecule-metal junctions at the single-molecule level has been developed to test the effects of the junction configuration on the thermopower properties. The method is based on dynamic switching between (thermo)electric current and thermoelectric voltage measurements. Two model systems, 4,4′-bipyridine (1) and 4,4′-diaminostilbene (2), have been scrutinized. Single-molecule conductance (G) and thermopower (S) values were obtained for the two most probable junction configurations of 1 and 2, each having two different conductance values, GH (high) and GL (low), where GH > GL. Thermopower values of S(GH) =6.4 ± 1.5 μV K-1 and S(GL) =7.0 ± 1.6 μV K-1 were obtained for the molecular junctions of 1 and values of S(GH) = +14.4 ± 3.5 μV K-1 and S(GL) = +10.4 ± 3.0 μV K-1 were obtained for the molecular junctions of 2. The GH and S(GH) values for 1 and 2 are consistent with previously reported results. Thermopower values obtained simultaneously with conductance measurements for both configurations of 2 during junction evolution are reported for the first time. This work shows that, within experimental error, both S values are the same for each molecule, i.e., S(GH) ≈ S(GL), and they do not depend on the molecular junction configuration. This is an important finding, which supports claims that thermopower is an intensive property of matter. DFT calculations of transmission functions combined with a non-equilibrium Green's function approach complete this study.

Název v anglickém jazyce

Does the Seebeck coefficient of a single-molecule junction depend on the junction configuration?

Popis výsledku anglicky

A new experimental method for the simultaneous determination of the electric and thermoelectric properties of metal-molecule-metal junctions at the single-molecule level has been developed to test the effects of the junction configuration on the thermopower properties. The method is based on dynamic switching between (thermo)electric current and thermoelectric voltage measurements. Two model systems, 4,4′-bipyridine (1) and 4,4′-diaminostilbene (2), have been scrutinized. Single-molecule conductance (G) and thermopower (S) values were obtained for the two most probable junction configurations of 1 and 2, each having two different conductance values, GH (high) and GL (low), where GH > GL. Thermopower values of S(GH) =6.4 ± 1.5 μV K-1 and S(GL) =7.0 ± 1.6 μV K-1 were obtained for the molecular junctions of 1 and values of S(GH) = +14.4 ± 3.5 μV K-1 and S(GL) = +10.4 ± 3.0 μV K-1 were obtained for the molecular junctions of 2. The GH and S(GH) values for 1 and 2 are consistent with previously reported results. Thermopower values obtained simultaneously with conductance measurements for both configurations of 2 during junction evolution are reported for the first time. This work shows that, within experimental error, both S values are the same for each molecule, i.e., S(GH) ≈ S(GL), and they do not depend on the molecular junction configuration. This is an important finding, which supports claims that thermopower is an intensive property of matter. DFT calculations of transmission functions combined with a non-equilibrium Green's function approach complete this study.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10405 - Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis)

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2021

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Materials Chemistry A

ISSN

2050-7488

e-ISSN

2050-7496

Svazek periodika

9

Číslo periodika v rámci svazku

32

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

9

Strana od-do

17512-17520

Kód UT WoS článku

000683040900001

EID výsledku v databázi Scopus

2-s2.0-85113145507