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Regulation of the Crystal Structure Leading to the Bandgap Widening and Phonon Scattering Increasing in Cu 3 SnS 4 ‐Cu 3 SbSe 3 Chalcogenides
Author(s) -
Zhao Lulu,
Lin Naiming,
Han Zhongkang,
Li Xie,
Wang Haiyun,
Cui Jiaolin
Publication year - 2019
Publication title -
advanced electronic materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.25
H-Index - 56
ISSN - 2199-160X
DOI - 10.1002/aelm.201900485
Subject(s) - materials science , chalcogenide , thermoelectric effect , band gap , ternary operation , crystal structure , phonon , valence (chemistry) , phonon scattering , condensed matter physics , thermoelectric materials , scattering , crystal (programming language) , optoelectronics , crystallography , thermal conductivity , optics , composite material , thermodynamics , chemistry , computer science , physics , programming language , organic chemistry
Cu 3 SnS 4 chalcogenide as a low‐cost, earth abundant thermoelectric material has recently attracted much attention. However, its Seebeck coefficient is rather low due to its metallic‐like behavior; therefore, substantial work is required to enhance its thermoelectric (TE) properties. In this work, an alternative method is proposed, that is, a regulation of the crystal structure through alloying with Cu 3 SbSe 3 . This regulation is realized by the incorporation of Sb and Se in the Cu 3 SnS 4 host frame with an addition of Cu 3 SbSe 3 , thus altering the bond lengths (CuS and SnS) and bond angles (SCuS and SSnS), and leading to widening of the bandgap and the convergence of top valence bands. At the same time, the lattice thermal conductivity reduces by ≈50% at high temperatures, mainly triggered by the crystal structure distortion and introduced point defects. The approach of crystal structure regulation may help design the properties of other ternary CuSn(Sb)S(Se) compounds for TE applications.