Enhanced thermoelectric properties of n-type Bi2Te2.7Se0.3 thin films through the introduction of Pt nanoinclusions by pulsed laser deposition

•We prepare Pt nanoinclusions in textured Bi2Te2.7Se0.3 thin films via PLD.•Thermoelectric property of the nanocomposite thin film can be great improved.•We report a feasible method to introduce nanoinclusions into high texture thin film.

This work demonstrates the first preparation of textured n-type Bi2Te2.7Se0.3 thin films with content-adjustable Pt nanoinclusions by pulsed laser deposition. Characterization results reveal that metallic Pt nanoinclusions are embedded in the semiconductor matrix at grain boundaries. Addition of Pt nanoinclusions results in a higher in-plane power factor based on the simultaneous increase in electrical conductivity and absolute Seebeck coefficient. Power factor of the optimized nanocomposite thin film reaches 3.51×10–3 W/mK2 at room temperature, which is a more than 20% enhancement as compared to the single phase Bi2Te2.7Se0.3 thin film. An even greater improvement in the in-plane ZT can be expected from a reduced thermal conductivity, as indicated by cross-plane thermal property measurement. This work highlights the feasibility of combining nanocomposite engineering with textured thin films to further improve thermoelectric performance.

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