Enhanced thermoelectric properties of n-type Bi_2Te_(2.7)Se_(0.3) thin films through the introduction of Pt nanoinclusions by pulsed laser deposition

摘要

This work demonstrates the first preparation of textured n-type Bi_2Te_(2.7)Se_(0.3) 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/mK~2 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.