WANG Wenjie 1, WANG Xiaojun 2
(1. Shaanxi Railway Engineering Vocational and Technical College, Weinan 714000, Shaanxi, China; 2. State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou University of Technology, Lanzhou 730050, Gansu, China)
Abstract: Based on the first principles, the effects of Ni and Te doping on the energy band and density of states of CoSb3 thermoelectric materials are simulated and analyzed. It is calculated that the band gap value is reduced from 0.350 eV to 0.199 eV, and the reduction of the band gap value improves the thermoelectric performance. Comparing the density of states of each atom, it is found that the doped sample exhibits the properties of an N-type semiconductor. The In0.3Co4-xNixSb12-yTey series thermoelectric material was prepared by hot-press sintering under the conditions of 600 ℃ and 40 MPa by solid-phase reaction method. The results show that the prepared In0.3Co4-xNixSb12-yTey thermoelectric material has uniform composition and no impurities. In the test temperature of 300 -800 K, the change trend of its Seebeck coefficient, thermal conductivity, and electrical conductivity is consistent with expectations. The thermal conductivity of In0.3Co3.5Ni0.5Sb11.5Te0.5 thermoelectric material is 700 K When the minimum value is 2.4 W•m-1•K-1, at 750 K, its thermoelectric figure of merit reaches the maximum value of 0.62.
Key words: doping; In filling; Ni atoms; Te atoms; thermoelectric figure of merit