Enhanced thermoelectric properties in p-type Bi_0.4Sb_1.6Te₃ alloy by combining incorporation and doping using multi-scale CuAlO₂ particles

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• 作者：Zijun Song ; Qihao Zhang ; Yuan Liu ; Zhenxing Zhou ; Xiaofang Lu ; Lianjun Wang ; Wan Jiang and Lidong Chen
• 刊名：physica status solidi (a)
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：214
• 期：1
• 全文大小：1696K
• ISSN：1862-6319

文摘

Multi-scale CuAlO₂ particles are introduced into the Bi_0.4Sb_1.6Te₃ matrix to synergistically optimize the electrical conductivity, Seebeck coefficient, and the lattice thermal conductivity. Cu element originating from fine CuAlO₂ grains diffuses into the Bi_0.4Sb_1.6Te₃ matrix and tunes the carrier concentration while the coarse CuAlO₂ particles survive as the second phase within the matrix. The power factor is improved at the whole temperatures range due to the low-energy electron filtering effect on Seebeck coefficient and enhanced electrical transport property by mild Cu doping. Meanwhile, the remaining CuAlO₂ inclusions give rise to more boundaries and newly built interfaces scattering of heat-carrying phonons, resulting in the reduced lattice thermal conductivity. Consequently, the maximum ZT is found to be enhanced by 150% arising from the multi-scale microstructure regulation when the CuAlO₂ content reaches 0.6 vol.%. Not only that, but the ZT curves get flat in the whole temperature range after introducing the multi-scale CuAlO₂ particles, which leads to a remarkable increase in the average ZT.