Improved\nThermoelectric Performance in n–type\nBi<sub>2</sub>(Te,Se)<sub>3</sub> Alloys through the Incorporation\nof Fe Nanoparticles

Herein,\nwe investigated the thermoelectric properties of Fe-BTS\n(Bi<sub>2</sub>Te<sub>3</sub>-based compound) samples fabricated through\nnanometal decoration and spark plasma sintering. We examined the effects\nof Fe nanoparticle (NP) addition on the power factor (PF), thermal\nconductivity (κ), and figure of merit (<i>ZT</i>)\nof the samples. The incorporation of Fe NPs led to a significant increase\nin the PF of the Fe-BTS samples, surpassing the performance of the\npristine sample by over 34%. This improvement is attributed to the\ncombined effects of carrier concentration tuning and low-energy carrier\nfiltering. Additionally, the thermal conductivity of the Fe-BTS samples\nwas significantly reduced due to enhanced phonon scattering at the\nincreased interfaces. Consequently, a maximum <i>ZT</i> value\nof 1.09 was achieved at 363 K for the Fe-BTS sample with an Fe content\nof 0.3 vol %. These findings highlight the crucial role of interface\nengineering in enhancing the thermoelectric properties of materials.