The study of thermoelectricity in molecular junctions is of fundamental interest for the development of various technologies including cooling (refrigeration) and heat-to-electricity conversion1,2,3,4. Recent experimental progress in probing the thermopower (Seebeck effect) of molecular junctions5,6,7,8,9 has enabled studies of the relationship between thermoelectricity and molecular structure10,11. However, observations of Peltier cooling in molecular junctions—a critical step for establishing molecular-based refrigeration—have remained inaccessible. Here, we report direct experimental observations of Peltier cooling in molecular junctions. By integrating conducting-probe atomic force microscopy12,13 with custom-fabricated picowatt-resolution calorimetric microdevices, we created an experimental platform that enables the unified characterization of electrical, thermoelectric and energy dissipation characteristics of molecular junctions. Using this platform, we studied gold junctions with prototypical molecules (Au–biphenyl-4,4′-dithiol–Au, Au–terphenyl-4,4′′-dithiol–Au and Au–4,4′-bipyridine–Au) and revealed the relationship between heating or cooling and charge transmission characteristics. Our experimental conclusions are supported by self-energy-corrected density functional theory calculations. We expect these advances to stimulate studies of both thermal and thermoelectric transport in molecular junctions where the possibility of extraordinarily efficient energy conversion has been theoretically predicted2,3,4,14.
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Dubi, Y. & Di Ventra, M. Colloquium: Heat flow and thermoelectricity in atomic and molecular junctions. Rev. Mod. Phys. 83, 131–155 (2011).
Finch, C. M., García-Suárez, V. M. & Lambert, C. J. Giant thermopower and figure of merit in single-molecule devices. Phys. Rev. B 79, 033405 (2009).
Bergfield, J. P., Solis, M. A. & Stafford, C. A. Giant thermoelectric effect from transmission supernodes. ACS Nano 4, 5314–5320 (2010).
Karlström, O., Linke, H., Karlström, G. & Wacker, A. Increasing thermoelectric performance using coherent transport. Phys. Rev. B 84, 113415 (2011).
Kim, Y., Jeong, W., Kim, K., Lee, W. & Reddy, P. Electrostatic control of thermoelectricity in molecular junctions. Nat. Nanotech. 9, 881–885 (2014).
Li, Y., Xiang, L., Palma, J., Asai, Y. & Tao, N. J. Thermoelectric effect and its dependence on molecular length and sequence in single DNA molecules. Nat. Commun. 7, 11294 (2016).
Reddy, P., Jang, S. Y., Segalman, R. A. & Majumdar, A. Thermoelectricity in molecular junctions. Science 315, 1568–1571 (2007).
Rincón-García, L. et al. Molecular design and control of fullerene-based bi-thermoelectric materials. Nat. Mater. 15, 289–293 (2016).
Widawsky, J. R., Darancet, P., Neaton, J. B. & Venkataraman, L. Simultaneous determination of conductance and thermopower of single molecule junctions. Nano Lett. 12, 354–358 (2012).
Aradhya, S. V. & Venkataraman, L. Single-molecule junctions beyond electronic transport. Nat. Nanotech. 8, 399–410 (2013).
Cui, L., Miao, R., Jiang, C., Meyhofer, E. & Reddy, P. Perspective: thermal and thermoelectric transport in molecular junctions. J. Chem. Phys. 146, 092201 (2017).
Tan, A. et al. Effect of length and contact chemistry on the electronic structure and thermoelectric properties of molecular junctions. J. Am. Chem. Soc. 133, 8838–8841 (2011).
Tan, A., Sadat, S. & Reddy, P. Measurement of thermopower and current-voltage characteristics of molecular junctions to identify orbital alignment. Appl. Phys. Lett. 96, 013110 (2010).
Sadeghi, H., Sangtarash, S. & Lambert, C. J. Oligoyne molecular junctions for efficient room temperature thermoelectric power generation. Nano Lett. 15, 7467–7472 (2015).
Callen, H. B. Thermodynamics: An Introduction to the Physical Theories of Equilibrium Thermostatics and Irreversible Thermodynamics (Wiley, New York, 1960).
Rowe, D. M. Thermoelectrics Handbook: Macro to Nano (CRC/Taylor & Francis, Boca Raton, 2006).
Huang, Z. et al. Local ionic and electron heating in single-molecule junctions. Nat. Nanotech. 2, 698–703 (2007).
Ioffe, Z. et al. Detection of heating in current-carrying molecular junctions by Raman scattering. Nat. Nanotech. 3, 727–732 (2008).
Ward, D. R., Corley, D. A., Tour, J. M. & Natelson, D. Vibrational and electronic heating in nanoscale junctions. Nat. Nanotech. 6, 33–38 (2011).
Lee, W. et al. Heat dissipation in atomic-scale junctions. Nature 498, 209–212 (2013).
Zotti, L. A. et al. Heat dissipation and its relation to thermopower in single-molecule junctions. New. J. Phys. 16, 015004 (2014).
Galperin, M., Saito, K., Balatsky, A. V. & Nitzan, A. Cooling mechanisms in molecular conduction junctions. Phys. Rev. B 80, 115427 (2009).
Wold, D. J. & Frisbie, C. D. Fabrication and characterization of metal–molecule–metal junctions by conducting probe atomic force microscopy. J. Am. Chem. Soc. 123, 5549–5556 (2001).
Choi, S. H., Kim, B. & Frisbie, C. D. Electrical resistance of long conjugated molecular wires. Science 320, 1482–1486 (2008).
Pauly, F. et al. Cluster-based density-functional approach to quantum transport through molecular and atomic contacts. New. J. Phys. 10, 125019 (2008).
Quek, S. Y. et al. Amine–gold linked single-molecule circuits: experiment and theory. Nano Lett. 7, 3477–3482 (2007).
Segal, D. & Agarwalla, B. K. Vibrational heat transport in molecular junctions. Annu. Rev. Phys. Chem. 67, 185–209 (2016).
Cui, L. et al. Quantized thermal transport in single-atom junctions. Science 355, 1192–1195 (2017).
Klöckner, J. C., Siebler, R., Cuevas, J. C. & Pauly, F. Thermal conductance and thermoelectric figure of merit of C60-based single-molecule junctions: electrons, phonons, and photons. Phys. Rev. B 95, 245404 (2017).
Lin, S. F. & Leonard, W. F. Thermoelectric power of thin gold films. J. Appl. Phys. 42, 3634–3639 (1971).
Ahlrichs, R., Bar, M., Haser, M., Horn, H. & Kolmel, C. Electronic-structure calculations on workstation computers — the program system TURBOMOLE. Chem. Phys. Lett. 162, 165–169 (1989).
Perdew, J. P. Density-functional approximation for the correlation energy of the inhomogeneous electron gas. Phys. Rev. B 33, 8822–8824 (1986).
Schafer, A., Horn, H. & Ahlrichs, R. Fully optimized contracted Gaussian-basis sets for atoms Li to Kr. J. Chem. Phys. 97, 2571–2577 (1992).
P.R. and E.M. acknowledge funding from the Office of Naval Research (N00014-16-1-2672, instrumentation), the Department of Energy (DE-SC0004871, scanning probe microscopy), and the National Science Foundation (CBET 1509691, ECCS 1407967, calorimetry). L.A.Z. and J.C.C. acknowledge funding from the Spanish MINECO (projects MAT2014-58982-JIN and FIS2014-53488-P, and FIS2017-84057-P). J.C.C. also thanks the Deutsche Forschungsgemeinschaft, the research programme SFB767 for sponsoring his stay at the University of Konstanz as Mercator Fellow. We acknowledge the Lurie Nanofabrication Facility and Michigan Center for Materials Characterization for facilitating the fabrication and calibration of devices.
The authors declare no competing financial interests.
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Cui, L., Miao, R., Wang, K. et al. Peltier cooling in molecular junctions. Nature Nanotech 13, 122–127 (2018). https://doi.org/10.1038/s41565-017-0020-z
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