Achievement of Giant Power Factor and Moderate ZT in Sb-Doped SnO2 Thin Films by Post-Growth Annealing Technique
摘要
In this work, we successfully enhanced the thermoelectric potential of SbSnO2 thin films via post-growth annealing. A giant power factor of 51.64 × 10−4 W m−1 K−2 and a moderate figure of merit (ZT) of 0.20 were achieved by annealing Sb-doped SnO2 thin films at 400°C. Thin films used in this study were synthesized using thermal evaporation followed by post-growth annealing at different temperatures. X-ray diffraction (XRD) data indicated that the as-grown sample has a mixed structure with SnO, SnO2, SbO, and SnSb phases, while the sample annealed at 350°C has a pure tetragonal SnO2 phase, and this phase completely converted into the SbO phase when the annealing temperature reached 400°C. Significant morphological changes were seen in the Sb-doped SnO2 samples by scanning electron microscopy (SEM), with the sample annealed at 400°C showing a mixed morphology of nanoparticles and nanowires. Electrical conductivity measurements indicate an enhancement in electrical conductivity with increasing annealing temperature, with the maximum value of 105.82 S/cm achieved for the sample annealed at 350°C. The Seebeck coefficient data show a decreasing trend, but annealing at 400°C caused a suddenly increase in the Seebeck coefficient to 105 × 10−4 V/K, which resulted in a giant power factor value of 51.64 × 10−4 W m−1 K−2. Furthermore, through optimization of the thermal conductivity and power factor, we achieved ZT of 0.20 in the sample annealed at 400°C.