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Large Seebeck effect by charge-mobility engineering.
Peijie Sun1, Beipei Wei1, Jiahao Zhang1
1Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Nature Communications
|June 26, 2015
Summary
A new source for the Seebeck effect, based on charge-carrier relaxation and temperature-dependent mobility, has been identified. This discovery offers a novel approach for designing improved thermoelectric materials.
Area of Science:
- Solid-state physics
- Materials science
- Thermoelectricity
Background:
- The Seebeck effect generates electric potential from temperature gradients in solids.
- Current research focuses on optimizing electronic structure for better thermoelectric performance.
- An energy-dependent density of states at the Fermi level typically dominates this effect.
Purpose of the Study:
- To demonstrate an alternative source of the Seebeck effect.
- To explore the role of charge-carrier relaxation and temperature-dependent mobility.
- To provide a new avenue for designing advanced thermoelectric materials.
Main Methods:
- Investigated the Seebeck effect in Ni-doped CoSb3.
- Analyzed charge-carrier relaxation mechanisms.
- Correlated mobility changes with Seebeck coefficient variations.
Main Results:
- Identified charge-carrier relaxation as a significant source of the Seebeck effect.
- Observed a marked change in mobility due to relaxation regime crossover in Ni-doped CoSb3.
- Demonstrated that rapid temperature-induced mobility changes contribute to the Seebeck coefficient.
Conclusions:
- Charge-carrier relaxation offers a new pathway to enhance the Seebeck effect.
- This mechanism explains features in previously elusive thermoelectric materials.
- The findings pave the way for novel thermoelectric material design strategies.
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