| AVS 60th International Symposium and Exhibition | |
| Advanced Surface Engineering | Friday Sessions |
| Session SE+EN-FrM |
| Session: | Surface Engineering for Energy Conversion and Harvesting |
| Presenter: | A.A. Voevodin, Air Force Research Laboratory |
| Authors: | A.A. Voevodin, Air Force Research Laboratory I. Altfeder, Air Force Research Laboratory K.A. Matveev, Argonne National Laboratory |
| Correspondent: | Click to Email |
The control of thermal transport through coupled metal and non-metal interfaces is critical for many applications, including electronic device operation, photovoltaic power generation, sensors, and many others. For design and engineering of such interfaces, the energy coupling between electrons and phonons for heat transfer needs be assessed. An atomic level thermometer was developed to experimentally study interfacial thermal conductivity on a single molecular scale using an inelastic electron tunneling spectroscopy (IETS) combined with scanning tunneling microscopy (STM). The IETS-STM had led to a discovery of vacuum phonon tunneling across nanometer contact gaps as it can probe electron-phonon coupling at atomic scale [1]. The further development of the STM-based spectroscopic imaging technique discussed here provides direct real-space imaging of electron-phonon coupling parameter [2]. This is demonstrated using the combination of STM and IETS for thin Pb islands epitaxially grown on 7x7 reconstructed Si(111). Electron-phonon interaction increases when the electron scattering at the Pb/Si(111) interface is diffuse and decreases when the electron scattering becomes specular. The effect is driven by transverse redistribution of the electron density inside a quantum well.
References:
[1] I. Altfeder, A. A. Voevodin, A. K. Roy, Physical Review Letters, 105 (2010) 166101.
[2] Igor Altfeder, K. A.Matveev, A. A. Voevodin, Physical Review Letters 109, 166402 (2012).