Title: Summary Thermoelectric Materials

Choose the correct statement.

- A thermoelectric material is capable to convert heat to electricity via the Seebeck effect or a temperature gradient into a voltage via the Peltier effect. (correct)
- A thermoelectric material is capable to convert heat to electricity via the Peltier effect or a temperature gradient into a voltage via the Seebeck effect.

- The effectiveness of a thermoelectric material is described by the figure of merit ZT, which takes into account the Seebeck coefficient, the electrical conductivity and the thermal conductivity. (correct)
- The effectiveness of a thermoelectric material is described by the figure of merit ZT, which takes into account the Peltier coefficient, the dielectric constant, the specific heat and the thermal diffusivity.

- In order to maximize the figure of merit ZT, we need to achieve high electrical conductivity, low thermal conductivity and high Seebeck coefficient. (correct)
- In order to maximize the figure of merit ZT, we need to achieve high thermal conductivity, low electrical conductivity and high Seebeck coefficient.

- High electrical conductivity is achieved for carriers with low effective mass and for materials with a high Density of States (DoS) at the Fermi level. (correct)
- High electrical conductivity is achieved for carriers with high effective mass and a narrow band gap.

- According to the Wiedemann-Franz law, the thermal conductivity is proportional to the electrical conductivity. (correct)
- According to the Wiedemann-Franz law, the thermal conductivity is inversely proportional to the electrical conductivity.

- However, it is still possible to minimize the thermal contribution from the phonons by introducing heavy atoms (with low phonon frequencies) and disorder that affects phonons but not electrons. (correct)
- However, it is still possible to minimize the thermal contribution from the phonons by introducing light atoms (with low phonon frequencies) and disorder that affects electrons but not phonons.

- A high Seebeck coefficient can be obtained with a strongly varying density of states around the Fermi energy. (correct)
- A high Seebeck coefficient can be obtained with a smooth density of states around the Fermi energy.

- In conclusion, the design of new thermoelectric materials is complex due to the many trade-offs between different requirements to maximize the figure of merit. (correct)
- In conclusion, the design of new thermoelectric materials is theoretically possible but difficult to implement due to production issues.