Thermoelectric properties of Al-doped ZnO thin films

We have prepared 2 % Al-doped ZnO (AZO) thin films on SrTiO₃ substrates by a pulsed laser deposition technique at various deposition temperatures (T _dep = 300-600 °C). The thermoelectric properties of AZO thin films were studied in a low temperature range (300-600 K). Thin film deposited at 300 °C is fully c-axis-oriented and presents electrical conductivity 310 S/cm with Seebeck coefficient -65 μV/K and power factor 0.13 × 10^-3 Wm^-1 K^-2 at 300 K. The performance of thin films increases with temperature. For instance, the power factor is enhanced up to 0.55 × 10^-3 Wm^-1 K ^-2 at 600 K, surpassing the best AZO film previously reported in the literature.