Boosting Thermoelectrics with Irradiation Damage
By irradiating Bi2Te3-based films with 3MeV alpha particles, the thermoelectric figure-of-merit of the films was found to be drastically improved, by a factor of up to ten, at the optimal irradiation dose.
Discovered that radiation damage can drastically boost thermoelectric performance of some materials by generating beneficial defects.
Significance and Impact
Defects in materials usually degrade the materials performance. Our discoveries and understanding enable methods to design and engineer material properties with intentionally introduced defects.
- Thermoelectrics represent a potentially huge source of clean, green energy. Figure-of-merit of TE materials is usually limited by anti-correlation between alpha (thermopower) and sigma (electrical conductivity).
- Irradiated Bi2Te3 films showed simultaneous enhancement of alpha and sigma were enhanced, by up to 70% and 200%, resp. Figure-of-merit enhanced up to 10x at optimal irradiation dose.
- Attributed to irradiation-created native defects acting multi-functionally as both electron donors and electron energy filters.