On-chip thermoelectric module comprised of oxide thin film legs

On-chip thermoelectric thin film modules containing 5 legs of n-type (Al_0.02Zn_0.98O) and 5 legs of p-type (Ca₃Co₄O₉) were fabricated on Al₂O₃, SrTiO₃ single crystal, and fused silica substrates by pulsed laser deposition technique. Performance of modules was evaluated using ad hoc customized system where the module was set vertically for temperature gradient. The maximum output power (P_max) was obtained on Al₂O₃ (0 0 0 1) single crystal substrate with temperature difference (ΔT)=230°C (T_h = 300 °C): P_max = 29.9 pW. The value of maximum output power increases with increase of temperature difference (ΔT). These results are encouraging for the practical applications of thermoelectric oxide thin films.