Yuta Fujimoto

Analysis of thermoelectric properties of amorphous InGaZnO thin film by controlling carrier concentration

We have investigated the thermoelectric properties of amorphous InGaZnO (a-IGZO) thin films optimized by adjusting the carrier concentration. The a-IGZO films were produced under various oxygen flow ratios. The Seebeck coefficient and the electrical conductivity were measured from 100 to 400 K. We found that the power factor (PF) at 300 K had a maximum value of 82 × 10−6 W/mK2, where the carrier density was 7.7 × 1019 cm−3. Moreover, the obtained data was analyzed by fitting the percolation model. Theoretical analysis revealed that the Fermi level was located approximately above the potential barrier when the PF became maximal. The thermoelectric properties were controlled by the relationship between the position of Fermi level and the height of potential energy barriers.

Thermoelectric properties of a-InGaZnO thin film

Thermoelectric properties of a-IGZO thin film were optimized by adjusting the carrier concentration. We found that the power factor (PF) has the maximum value of 82 × 10^-6 W / mK² at 300 K, where the carrier density was 7.70 × 10¹⁹ cm^-3. Additionally, measured data was analyzed by fitting the percolation model. Theoretical analysis revealed that the Fermi level is located on right over the potential barrier when the PF becomes maximum.