Improved thermoelectric performance of p-type Bi0.5Sb1.5Te3 through Mn doping at elevated temperature. (August 2018)

• Record Type: Journal Article
• Authors: Qin, Haixu; Liu, Yuan; Zhang, Zongwei; Wang, Yumei; Cao, Jian; Cai, Wei; Zhang, Qian; Sui, Jiehe
• Is Part Of: Materials today physics. Volume 6(2018)
• Page Start: 31
• Page End: 37
• Publication Date: 2018-08
• Subjects: Bi0.5Sb1.5Te3 -- Mn doping -- Intrinsic excitation -- Thermoelectric properties; Materials science -- Periodicals; Physics -- Periodicals; Electronic journals; 530.41
• DOI: 10.1016/j.mtphys.2018.07.002
• Languages: English
• ISSNs: 2542-5293

Abstract

Abstract: Bi2 Te3 -based compounds are the well-manufactured thermoelectric materials working near room temperature, however, less promising to be used in the low-temperature power generation due to the early onset of the intrinsic excitation. In this work, we used manganese (Mn) to substitute antimony (Sb) in the lattice of Bi0.5 Sb1.5 Te3 to dramatically increase the electrical conductivity and higher temperature Seebeck coefficient and decrease the bipolar thermal conductivity, leading to enhancement in both maximum ZT ∼ 1.3 at 430 K and average ZT above 1.1 at the temperature range from 300 K to 573 K, which is vital to obtain high conversion efficiency for low-temperature power generation. Graphical abstract: A tiny amount of Mn could sharply increase the carrier concentration without changing the electronic band structure, consequently leading to delay the appearance of intrinsic excitation and improve PF values in the whole temperature range. Meanwhile, the lattice and bipolar thermal conductivity are both greatly reduced. Therefore, a very high ZT of ∼1.3 at 430 K and it's ZT ave of 1.1 between 303 and 573 K are achieved, which is vital to push the application of the Bi2 Te3 -based thermoelectric materials at elevated temperature. Image 1 Highlights: The power factor is enhanced in the whole temperature range for Mn x Bi0.5 Sb1.5- x Te3 samples. Both lattice and bipolar thermal conductivity are greatly reduced. A peak ZT of ∼1.3 at 430 K and average ZT of ∼1.1 between 300 K and 573 K are achieved.