Enhanced thermoelectric properties in p‐type Bi0.4Sb1.6Te3 alloy by combining incorporation and doping using multi‐scale CuAlO2 particles

• Published in: Physica status solidi. A, Applications and materials science Applications and materials science, 2017-01, Vol.214 (1), p.n/a
• Main Authors: Song, Zijun, Zhang, Qihao, Liu, Yuan, Zhou, Zhenxing, Lu, Xiaofang, Wang, Lianjun, Jiang, Wan, Chen, Lidong
• Format: Article
• Language: English
• Subjects: Atoms & subatomic particles; Bi0.4Sb1.6Te3 alloy; Carrier density; Doping; Electrical resistivity; Filtration; Heat conductivity; Heat transfer; multi‐scale CuAlO2 particles; Particle physics; Phonons; Power factor; Thermal conductivity; thermoelectric properties
• ISSN: 1862-6300; 1862-6319
• DOI: 10.1002/pssa.201600451

Multi‐scale CuAlO2 particles are introduced into the Bi0.4Sb1.6Te3 matrix to synergistically optimize the electrical conductivity, Seebeck coefficient, and the lattice thermal conductivity. Cu element originating from fine CuAlO2 grains diffuses into the Bi0.4Sb1.6Te3 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.