Enhanced thermoelectric performance of n-type SnxBi2Te2.7Se0.3 based composites embedded with in-situ formed SnBi and Te nanoinclusions. (15th September 2020)

• Record Type: Journal Article
• Authors: Jabar, Bushra; Qin, Xiaoying; Mansoor, Adil; Ming, Hongwei; Huang, LuLu; Zhang, Jian; Danish, Mazhar Hussain; Li, Di; Zhu, Chen; Zhang, Jinhua; Xin, Hongxing; Song, Chunjun
• Is Part Of: Composites. Number 197(2020)
• Publication Date: 2020-09-15
• Subjects: Thermoelectric material -- Bi2Te2.7Se0.3 -- Sn doping -- Hot pressing -- Figure of merit; Composite materials -- Periodicals; Materials science -- Periodicals; Composite materials; Periodicals; Electronic journals; 620.118
• DOI: 10.1016/j.compositesb.2020.108151
• Languages: English
• ISSNs: 1359-8368

Abstract

Abstract: Although n-type Bi2 Te3 -based alloys are state-of-the-art thermoelectric material, their efficiency is still too low to satisfy its wide applications. Hence, it is imperative to improve the thermoelectric performance of n-type Bi2 Te2.7 Se0.3 (BTS). Here, we show that through a facile method of Sn addition in BTS a new Snx Bi2 Te2.7 Se0.3 based nanocomposite embedded with in-situ formed SnBi and Te nanoinclusions ((SnBi + Te)/Snx Bi2 Te2.7 Se0.3 ) is constructed, and its thermoelectric performance is enhanced substantially as compared to pristine BTS. Specifically, addition of 0.2 wt% of Sn in BTS causes 38% increase in power factor (PF) and 40% reduction in lattice thermal conductivity. The increased PF mainly comes from elevated Seebeck coefficient due to intensified energy dependent electron scattering caused by the interface potentials; while the reduced thermal conductivity originates from enhanced phonon scattering by the embedded nanoinclusions. Consequently, both high maximum figure of merit ZT (ZTmax = 1.11 at ~370 K) and large average ZT (ZTave = 1.03 at T = 300 K–500 K) are achieved for this sample, which are respectively 76% and 80% higher than those of BTS studied here. Graphical abstract: Image 1 Sn doped n-type Bi2 Te2.7 Se0.3 (BTS) based composites with in-situ formed SnBi and Te nanoinclusions are realized via a facile approach, which exhibit large figure of merit ZT max = 1.11 and high ZT ave = 1.03 owing to simultaneously enhanced power factor and phonon blocking. Highlights: Via a facile Sn addition both doping and in-situ nanocompositing are realized. A new nanocomposite (SnBi + Te)/Snx Bi2 Te2.7 Se0.3 is constructed through adding Sn. A large ZT ave = 1.03 in range of 300K–500K is achieved in this new composite system. The large ZT is realized via synergy of enhanced thermopower and phonon blocking.