Is there are some methods to increase the ZT of thermoelectric, and these methods no not have interdependence effect to the Seebeck coefficient, electron conductivity and thermal conductivity .
This is to say these methods not including the increasing carrier concentration, which can increase electron conductivity but normally decrease Seebeck coefficient at the same time.
Dear Yue Wang:
There is !
Have you heard about the Energy Filtering mechanism, either for electrons as for phonons ?
I'm leaving you here three good papers so you can get the general idea of the physics of this mechanism,
I work with the thermoelectric material Bi2Te3 , and we are trying to improve the Figure of Merit , and one of the ideas we are working on, is increasing the Power Factor (S2sigma) by increasing the Seebeck coefficient of this material,
what material are you working with ? What is its commun value of ZT so far ?
Let me know if we can discuss further about this topic
Best wishes !
Dear Yue Wang:
You are welcome!,
basically, the idea is to insert nanostructures of some particular kind in your material, preferencially a policrystalline material, since the policrystalline materials are better thermoelectric efficient materials than monocrystals, in general. Due to the grain boundaries.
There are a few techniques for the inclusion of the nanoestructures, this can be integrated inside the grains as isolated segregates, or as bi-layers making part of the grain, or inside the grain boundaries, as many single nanostructures, or just melted nanoparticles within the grain boundary.
The most used materials are, Al2O3 and ZnO nps , also pure Cu, Bi or Sb nanoparticles, as well as carbon nanostructures like carbon nanotubes or graphite or graphene nanoplatelets.
Regards !
There are also approaches that involve mechanisms like resonant energy levels in the band structure (Article Resonant levels in bulk thermoelectric semiconductors
) or coupling electrons to other types of excitations, like magnons (Article Magnon-drag thermopower and Nernst coefficient in Fe and Co
)
Dear Franklin and Stephen R. Boona
Very thanks for your answer and supported.
The method of increased scattering effect, by nano-structuring, de-coupling...., can decrease the thermal conductivity, however the mobility was also decreased by scattering. the exist method to increase the ZT normally have interdependent effect among Seebeck coefficient, electron conductivity and thermal conductivity. That's why ZT value was limited.
So, maybe an independent factor will good for the increasing of ZT, which can increase one part without decrease another part.
Dear Yue Wang :
Did you read the article ?
Have in your group planned for the inclusions of some nanostrucutures on the polycrystalline matrix of the materials you guys work with ?
Did this article gave you some ideas ?
Regards ! :)
- Badges
- Science topic
- Similar topics
- Linguistics
- Composition Studies
- Publication