Enhanced thermoelectric power factor of magnetron Co-sputtered Pd-added Bi2Te3 thin films

The study on Pd-added Bi2Te3 thin films involved the preparation of these films using the co-magnetron sputtering technique. The process included fixing the Bi:Te (2:3) target at 30 W of pulsed dc-power while varying the Pd target on the sputtering power in a range of 0–12 W. All deposited film thicknesses were maintained at 500 nm. The investigation of the thermoelectric power factor (PF) of thin films with varying Pd-adding contents revealed interesting results. The Pd contents were increased by increasing the sputtering power on the Pd target. The PdTe2 phase was initiated, starting at 4 W of Pd sputtering power, resulting in a heterogeneous alloy of Bi2Te3 and PdTe2 phase. The increase in the Pd content led to a reduction in the electrical resistivity. At the same time, an appropriate Pd-adding concentration could cause the rise of the Seebeck coefficient and power factor. The maximum power factor of 3.06 mW m−1 K−2 (ρ = 14.63 μΩ m, S = −212 μV K−1) at room temperature was achieved on a Pd-added Bi2Te3 thin film (Pd-4W). This finding underscores the potential of Pd's most appropriate adding content into Bi2Te3 thin films for thermoelectric energy harvesting applications.