Enhancing the thermoelectric performance of CexBi2S3 by optimizing the carrier concentration combined with band engineering. Issue 47 (23rd November 2017)

• Record Type: Journal Article
• Authors: Pei, Jun; Zhang, Li-Juan; Zhang, Bo-Ping; Shang, Peng-Peng; Liu, Yao-Chun
• Is Part Of: Journal of materials chemistry. Volume 5:Issue 47(2017)
• Page Start: 12492
• Page End: 12499
• Publication Date: 2017-11-23
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c7tc04082b
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : Bi2 S3 is a promising low-cost thermoelectric material, but effective chemical modification is needed for its performance enhancement. Ce is an effective n-type doping element for Bi2 S3 based materials owing to optimized carrier concentration and band engineering. Abstract : Bi2 S3 is a promising low-cost thermoelectric material, but effective chemical modification is needed for its performance enhancement. In this work, we have investigated the effect of Ce on the electronic structure, phase structure, microstructure and TE properties of Ce x Bi2 S3 ( x = 0, 0.01, 0.03, 0.05) fabricated by combining mechanical alloying and spark plasma sintering. The calculated formation energy (Δ E F ) indicates that Ce will enter into interstitial sites of Bi2 S3 when substitutional sites are saturated. The electronic structure indicates that Ce doping produces a doping band which would reduce E g and increase m * of pristine Bi2 S3, and in turn enhancing n H . When x < 0.03, μ H and n H increased simultaneously due to the dominant effect of ionized impurity scattering. Owing to the collaborative optimization of n H, μ H, m *, a peak ZT value of 0.33 was obtained at 573 K at x = 0.03, along with a maximum PF value of 298 μW m −1 K −2, which is about three times higher than that of the pristine Bi2 S3 .