Influence of Core-Shell Structure on Thermoelectric Properties of Zn0.98Al0.02O

Al doped ZnO powders were fabricated by co-precipitation, and then coated with different quantity TiO2, forming Zn0.98Al0.02O@TiO2 core-shell heterogeneous structure, which was at last sintered to ceramics by SPS. The result shows that the electrical and thermal properties both are optimized with TiO2 coating. The power factor of 15wt% TiO2 coated sample improves by about 10% compared with that of the uncoated sample at 1023 K, and the thermal conductivity of 15 wt% TiO2 coated sample declines by about 30% compared with that of the uncoated sample. As a result, the maximum ZT value is enhanced by about 43% from 0.030 of the uncoated sample to 0.043 of 15 wt% TiO2 coated sample at 1023 K, which shows that the forming of Zn0.98Al0.02O@TiO2 core-shell heterogeneous structure is an effective approach to enhance the thermoelectric properties of ZnO.