Tuning of Thermopower in Molecular Junctions by Molecularly Controlled Sculpting of the Density of States in Their Leads.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 42474267.
- Also identified by DOI 10.1021/acs.nanolett.6c02296.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Molecular junctions are promising for (low power) thermoelectric applications, providing their transmission landscape can be made sufficiently nonlinear at the Fermi level to efficiently break their electron/hole transport symmetry in response to a temperature gradient. We present a method to induce such nonlinearity leading to thermopower values of |<i>S</i>| > 0.5 mV/K. The method is applicable to metal-molecules-semimetal junctions in which a space charge region is formed within the semimetal with a characteristic length perpendicular to the interface that can be tuned to become comparable to the Fermi wavelength of the semimetal. Under such conditions, the interfacial density of states within this lead is quantized at energies that can be tuned to reside within ∼<i>k</i><sub><i>B</i></sub><i>T</i> from the Fermi level by varying the molecular length. The resulting conductance behavior within this energy range becomes sufficiently steep to substantially break electron/hole transport symmetry, with ensuing high thermopower values.