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Thermoelectric Property Studies on Cu‐Doped n‐type Cu x Bi 2 Te 2.7 Se 0.3 Nanocomposites
Author(s) -
Liu WeiShu,
Zhang Qinyong,
Lan Yucheng,
Chen Shuo,
Yan Xiao,
Zhang Qian,
Wang Hui,
Wang Dezhi,
Chen Gang,
Ren Zhifeng
Publication year - 2011
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201100149
Subject(s) - materials science , thermoelectric effect , copper , reproducibility , figure of merit , hot pressing , nanocomposite , doping , thermoelectric materials , thermal conductivity , analytical chemistry (journal) , nanotechnology , composite material , metallurgy , optoelectronics , thermodynamics , statistics , physics , mathematics , chemistry , chromatography
Abstract Combining high energy ball‐milling and hot‐pressing, significant enhancements of the thermoelectric figure‐of‐merit ( ZT ) have been reported for p‐type Bi 0.4 Sb 1.6 Te 3 nanocomposites. However, applying the same technique to n‐type Bi 2 Te 2.7 Se 0.3 showed no improvement on ZT values, due to the anisotropic nature of the thermoelectric properties of n‐type Bi 2 Te 2.7 Se 0.3 . Even though texturing was effective in improving peak ZT of Bi 2 Te 2.7 Se 0.3 from 0.85 to 1.04, reproducibility from batch to batch remains unsatisfactory. Here, we show that good reproducibility can be achieved by introducing an optimal concentration of 0.01 copper (Cu) per Bi 2 Te 2.7 Se 0.3 to make Cu 0.01 Bi 2 Te 2.7 Se 0.3 samples. A peak ZT value of 0.99 was achieved in Cu 0.01 Bi 2 Te 2.7 Se 0.3 samples without texturing. With texturing by re‐pressing, the peak ZT was increased to 1.06. Aging in air for over 5 months did not deteriorate but further improved the peak ZT to 1.10. The mechanism by which copper improves the reproducibility, enhances the carrier mobility, and reduces the lattice thermal conductivity is also discussed.