Achieving high thermoelectric performance through constructing coherent interfaces and building interface potential barriers in n-type Bi2Te3/Bi2Te2.7Se0.3 nanocomposites. Issue 32 (2nd August 2019)

• Record Type: Journal Article
• Authors: Jabar, Bushra; Qin, Xiaoying; Li, Di; Zhang, Jian; Mansoor, Adil; Xin, Hongxing; Song, Chunjun; Huang, Lulu
• Is Part Of: Journal of materials chemistry. Volume 7:Issue 32(2019)
• Page Start: 19120
• Page End: 19129
• Publication Date: 2019-08-02
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c9ta05798f
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : Through incorporation of isostructural Bi2 Te3 nanoinclusions in n-type Bi2 Te2.7 Se0.3 we achieve unprecedented energy-conversion efficiency η = 10.5% with record high ZT max = 1.35. Abstract : Although Bi2 Te2.7 Se0.3 is the best n-type thermoelectric material near room temperature, its energy-conversion efficiency η reported so far is still low. Hence, it is imperative to increase its η so as to realize widespread applications in heat recovery. Here, we show that through incorporation of Bi2 Te3 (BT) nanoinclusions in Bi2 Te2.7 Se0.3 one can construct a large number of coherent phase boundaries and build effective interface potential barriers, based on which high electron mobility and energy-dependent carrier scattering are realized simultaneously. As a result, as large as 11% elevation of power factor is reached besides a large drop (53% at 300 K) of lattice thermal conductivity in the composite with 0.5 vol% BT nanoinclusions. Consequently, both a record high figure of merit ZT max = 1.35 (at 414 K) and a record large ZT ave = 1.28 are achieved in the operating temperature range of 300–525 K, which allow us to obtain an unprecedented conversion efficiency η = 10.5%. The present work demonstrates that incorporation of isostructural nanoinclusions in Bi2 Te2.7 Se0.3 is an effective approach to improve its thermoelectric performance.