Herein, we report a significant enhancement of the thermoelectric power factor in polycrystalline Ga-doped ZnO. Despite its higher carrier concentration, the Seebeck coefficient of Zn 0.985Ga 0.015O was larger than that of Zn 0.990Ga 0.010O benefiting from an enhancement of the density of states (DOS) effective mass. A gradual increase in the compressive stress with Ga substitution gave rise to a higher DOS at the bottom of the conduction band. An enlarged solution limit of Ga in the ZnO matrix due to a lower firing temperature accelerated the chemical compression. A single phase n-type Zn 0.985Ga 0.015O bulk exhibited a power factor of 12.5 μWcm -1 K -2.
Bibliographical noteFunding Information:
This work was supported by the Fundamental R&D Program for Core Technology of Materials (Grant No. K0006007) funded by the Ministry of Knowledge Economy, Korea.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)