Band Structure Engineering of Thermoelectric Materials- GeTe

Jing ZhiLiang

Nov 4 2015

Content• Introduction of project- Objective- Materials- Method- Tool

Objective• Enhance Thermoelectric Materials Performance by increasing figure of merit:

Power factor is mainly determined by electronic structure

Materials

GeTe (Gemanium Telluride):Thermoelectric materialNarrow band gap semiconductorRhombohedral structureRock-Salt Structure(~700K)

Brillouin Zone for FCC:

http://optiwave.com/optifdtd-manuals/fdtd-fcc-lattices-of-air-spheres-in-dielectric/

Method• 2 phenomena: band convergence and resonant state

1. Pei, Y., et al., Convergence of electronic bands for high performance bulk thermoelectrics. Nature, 2011. 473(7345): p. 66-9.2. Peng, H., et al., Electronic structure and transport properties of doped PbSe. Physical Review B, 2011. 84(12).

Band convergence & Resonant state Increase of S and σ

Method

• Objective Enhance the phenomenon of Band Convergence and Resonant State

• Materials Doping Control parameter: 1. Type of dopant (Ba, In, Ca, Hg, Zn, etc.) 2. Dose

• Evaluate the doping effects Plot band structure and DOS

Tool• VASPCalculate band structure and DOS for different dopants and different dosage

● INCAR● POSCAR● POTCAR● KPOINTS