Enhanced thermoelectric properties of Au nanodot-included Bi2Te3 nanotube composites

Herein, we report on a scalable synthesis of Au nanodot (Au-ND)/Bi 2 Te 3 nanotube (BT-NT) nanocomposites by the bottom-up synthesis of hybrid raw materials and subsequent spark plasma sintering, and their thermoelectric properties were systematically compared with those of Au-doped Bi 2 Te 3 compounds. The Au nanodots were included as seeds and co-crystallized in the crystal growth of BT-NTs, which were well-dispersed in the Bi 2 Te 3 matrix as nanoinclusions (10-20 nm). The thermoelectric performance ( ZT ) of the Au-ND/BT-NT nanocomposite was found to be enhanced by ∼67%, compared to pristine Bi 2 Te 3 due to electron energy filtering and phonon scattering effects in the presence of embedded Au-NDs. The resulting compound showed an enhanced power factor (23.0 × 10 −4 W m −1 K −2 @ 440 K, 27% improvement) and a reduced lattice thermal conductivity (0.47 W m −1 K −1 @ 440 K, 22% reduction). The peak ZT value of the present compound (0.95 @ 480 K) is larger than that of n-type single crystalline Bi 2 (Te,Se) 3 , which is one of the highest among the reported values for n-type Bi 2 Te 3 -based materials synthesized using a soft chemical route. Herein, we report on a scalable synthesis of Au nanodot (Au-ND)/Bi 2 Te 3 nanotube (BT-NT) nanocomposites by the bottom-up synthesis of hybrid raw materials and subsequent spark plasma sintering, and their thermoelectric properties were systematically compared with those of Au-doped Bi 2 Te 3 compounds.