| Autor: |
Hu Q; College of Physics, Sichuan University, Chengdu610064, P. R. China., Luo D; Faculty of Engineering, University of Nottingham, University Park, Nottingham999020, U.K., Guo J; Key Laboratory of Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu610064, P. R. China., Qiu W; Key Laboratory of Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu610064, P. R. China., Wu X; Nuclear Power Institute of China, Chengdu, Sichuan610041, P. R. China., Yang L; School of Materials Science & Engineering, Sichuan University, Chengdu610064, China., Wang Z; Sichuan Research Center of New Materials, Institute of Chemical Materials, China Academy of Engineering Physics, 596 Yinhe Road, Shuangliu, Chengdu610200, P. R. China., Cui X; Sichuan Research Center of New Materials, Institute of Chemical Materials, China Academy of Engineering Physics, 596 Yinhe Road, Shuangliu, Chengdu610200, P. R. China., Tang J; College of Physics, Sichuan University, Chengdu610064, P. R. China.; Key Laboratory of Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu610064, P. R. China. |
| Abstrakt: |
High-energy-conversion Bi 2 Te 3 -based thermoelectric generators (TEGs) are needed to ensure that the assembled material has a high value of average figure of merit ( ZT ave ). However, the inferior ZT ave of the n-type leg severely restricts the large-scale applications of Bi 2 Te 3 -based TEGs. In this study, we achieved and reported a high peak ZT (1.33) of three-dimensional (3D)-printing n-type Bi 2 Te 2.7 Se 0.3 . In addition, a superior ZT ave of 1.23 at a temperature ranging from 300 to 500 K was achieved. The high value of ZT ave was obtained by synergistically optimizing the electronic- and phonon-transport properties using the 3D-printing-driven defect engineering. The nonequilibrium solidification mechanism facilitated the multiscale defects formed during the 3D-printed process. Among the defects formed, the nanotwins triggered the energy-filtering effect, thus enhancing the Seebeck coefficient at a temperature range of 300-500 K. The effective scattering of wide-frequency phonons by multiscale defects reduced the lattice thermal conductivity close to the theoretical minimum of ∼0.35 W m -1 k -1 . Given the advantages of 3D printing in freeform device shapes, we assembled and measured bionic honeycomb-shaped single-leg TEGs, exhibiting a record-high energy conversion efficiency (10.2%). This work demonstrates the great potential of defect engineering driven by selective laser melting 3D-printing technology for the rational design of advanced n-type Bi 2 Te 2.7 Se 0.3 thermoelectric material. |
