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Energy Harvesting Through Thermoelectricity: An Atomic Scale Approach
Carlos Untiedt
9/5/11 2
- C. Untiedt
Alicante
Energy Harvesting Through Thermoelectricity: An Atomic Scale - - PowerPoint PPT Presentation
Energy Harvesting Through Thermoelectricity: An Atomic Scale - - PowerPoint PPT Presentation
Energy Harvesting Through Thermoelectricity: An Atomic Scale Approach Carlos Untiedt LT-NanoLab, Dept Fsica Aplicada Universidad de Alicante, Spain Alicante C. Untiedt 9/5/11 2 LT-Nanolab: Low temperatures and Nanosystems Laboratory C.
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LT-Nanolab: Low temperatures and Nanosystems Laboratory
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- C. Untiedt
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4 05/09/11 Carlos Untiedt
Study Electronic Transport of small structures
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Energy Harvesting Through Thermoelectricity: An Atomic Scale Approach
Thermoelectricity should be considered for energy
harvesting towards Zero Power ICT
Research should be done at the nanoscale (atomic and
molecular) to improve thermoelectrics
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The Seebeck effect
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S depends on:
- Density of +/- chargers
at Fermi energy
- Phonon drag
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Figure of Merit (ZT) Figure of Merit (ZT)
Figure of Merit (ZT)
ZT is related to the thermodynamic efficiency,
✔ ZT about 1 → good; ✔ ZT about 3–4 → thermoelectrics
compete with mechanical devices in efficiency. Now the best reported ZT values are in the 2–3 range. Much of the research in thermoelectric materials has focused on increasing S and reducing κ by manipulating the nanostructure of the materials.
- J. Syder (2003)
http://www.thermoelectrics.caltech.edu/thermoelectrics/index.html
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Cronin B. Vining . Nature Materials 8, 83 - 85 (2009)
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New opportunities in atomic and molecular conductors
Basic research through Scanning Tunneling Microscopies and related techniques
- Y. Dubi and M. Di Ventra. Rev. Mod. Phys. 83, 131 (2011)
- Density of states can be
“engineered”
- We can have a huge
amount of Seebeck devices
- It could make possible to
design on-chip peltier/seebeck devices
- Make use of small T
gradients
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Carlos Untiedt
Seebeck in molecules
Reddy et al. Science 315, 1568 (2007)
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Seebeck in MCBJ Seebeck in MCBJ
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Nature 458, 1150 (2009) Special DOS coming from quantum effects as resonant states or electron correlation effects such as “Kondo”
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Carlos Untiedt
Spin Seebeck effect Spin Seebeck effect
K.S. Uchida et al. Nature 455, 778 (2008) New oportunities: using temperature gradients to build-up spin separation for spintronic devices to be combined with other new technologies (Topological Insulators)
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Sumary Sumary
- Thermoelectricity constitutes an opportunity towards Zero Power ICT
- There has been a great advance in Thermoelectrics in the last decade
- Nanomaterials are good candidates for improving thermoelectric
devices
Issues Issues
- Seebeck coefficients and merit figures have to be properly understood
and improved
- Nanostures including molecular and atomic conductors have to be
further studied
- Integration of nanostructures in large devices should be implemented