Journal Article

Thermoelectricity in Molecular Junctions

Reddy, Pramod, Majumdar, Arun, Segalman, Rachel A., Jang, Sung-Yeon

2007

Overview

By trapping molecules between two gold electrodes with a temperature difference across them, the junction Seebeck coefficients of 1,4-benzenedithiol (BDT), 4,4′-dibenzenedithiol, and 4,4\"-tribenzenedithiol in contact with gold were measured at room temperature to be +8.7 ± 2.1 microvolts per kelvin (μV/K), +12.9 ± 2.2 μV/K, and +14.2 ± 3.2 μV/K, respectively (where the error is the full width half maximum of the statistical distributions). The positive sign unambiguously indicates p-type (hole) conduction in these heterojunctions, whereas the Au Fermi level position for Au-BDT-Au junctions was identified to be 1.2 eV above the highest occupied molecular orbital level of BDT. The ability to study thermoelectricity in molecular junctions provides the opportunity to address these fundamental unanswered questions about their electronic structure and to begin exploring molecular thermoelectric energy conversion.

• Publisher: American Association for the Advancement of Science,The American Association for the Advancement of Science
• Subject: Ambient temperature / Applied sciences / Chemical engineering / Compound structure devices / Contact / Electric potential / Electrodes / Electronics / Energy conversion / Error analysis / Exact sciences and technology / Fermi surfaces / Gold / Heterojunctions / Histograms / Materials / Materials science / Molecular biology / Molecular electronics, nanoelectronics / Molecules / Seebeck effect / Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices / Statistical distributions / Temperature gradients / Thermal energy / Thermoelectricity