Thermoelectric transport properties of Cu nanoprecipitates embedded Bi_{2 Te 2.7} Se_0.3

We suggest a simple and scalable synthesis to prepare Cu-Bi_{2 Te 2.7} Se_0.3 (Cu-BTS) nanocomposites. By precipitating Cu nanoparticle (NP) in colloidal suspension of as-exfoliated BTS, homogeneous mixtures of Cu NP and BTS nanosheet were readily achieved, and then the sintered nanocomposites were fabricated by spark plasma sintering technique using the mixed powder as a raw material. The precipitated Cu NPs in the BTS matrix effectively generated nanograin (BTS) and heterointerface (Cu/BTS) structures. The maximum Z T of 0.90 at 400 K, which is 15% higher compared to that of pristine BTS, was obtained in 3 vol% Cu-BTS nanocomposite. The enhancement of Z T resulted from improved power factor by carrier filtering effect due to the Cu nanoprecipitates in the BTS matrix.