Mechanical Property of SnSe Single Crystal Prepared via Vertical Bridgman Method

doi:10.15541/jim20200184

Abstract

Abstract:

Ⅳ-Ⅵ SnSe single crystal is an attractive thermoelectric (TE) material due to its outstanding TE behavior and environment friendly charactistic. In this work, an effective way for SnSe single crystal growth was explored, and the mechanical property of the as-prepared product was investigated. Undoped SnSe single crystal with accurate stoichiometric ratio was successfully grown via a vertical Bridgman method. The as-grown SnSe single crystal has standard orthorhombic Pnma space group at room temperature. It is easy to cleave along (100) plane because of its weak link between adjacent Sn-Se layers. Microindentation test reveals that SnSe single crystal is a very soft material as its average Vickers microhardness HV is only 53 MPa under 0.01-0.05 kg applied loads. However, it displays excellent fracture toughness due to strong heteropolar bonds between Sn and Se atoms inside (100) plane. The friction coefficient COF on (100) is increased from 0.09 to 0.8 as the scratch load is added from 5 to 300 mN. This work is of great significance to provide the mechanical property of SnSe single crystal.

Key words: SnSe single crystal, vertical Bridgman method, mechanical property

CLC Number:

TQ174

JIN Min, BAI Xudong, ZHAO Su, ZHANG Rulin, CHEN Yuqi, ZHOU Lina. Mechanical Property of SnSe Single Crystal Prepared via Vertical Bridgman Method[J]. Journal of Inorganic Materials, 2021, 36(3): 313-318.

Figures/Tables 7

References 21

[1]	BISWAS K, HE J Q, BLUM I D, et al. High-performance bulk thermoelectrics with all-scale hierarchical architectures. Nature, 2012,489(7416):414-418. DOI URL PMID
[2]	DISALVO F J. Thermoelectric cooling and power generation. Science, 1999,285(5428):703-706. DOI URL PMID
[3]	SNYDER G J, TOBERER E S. Complex thermoelectric materials. Nature Materials, 2008,7(2):105-114. DOI URL PMID
[4]	TRIPATHI M N, BHANDARI C M. High-temperature thermoelectric performance of Si-Ge alloys. Journal of Physics- Condensed Matter, 2003,15(31):5359. DOI URL
[5]	ZHAO L D, LO S H, ZHANG Y, et al. Ultralow thermal conductivity and high thermoelectric figure of merit in SnSe crystals. Nature, 2014,508(7496):373-377. DOI URL
[6]	ZHAO L D, TAN G, HAO S, et al. Ultrahigh power factor and thermoelectric performance in hole-doped single-crystal SnSe. Science, 2015,351(6269):141. DOI URL PMID
[7]	PENG K L, HUI S, ZHOU X Y, et al. Broad temperature plateau for high ZTs in heavily doped p-type SnSe single crystals. Energy & Environmental Science, 2016,9(2):454-460.
[8]	CHANG C, WU M, HE D, et al. 3D charge and 2D phonon transports leading to high out-of-plane ZT in n-type SnSe crystals. Science, 2018,360:778-783. DOI URL PMID
[9]	DUONG A T, NGUYEN V Q, DUVJIR G, et al. Achieving ZT=2.2 with Bi-doped n-type SnSe single crystals. Nature Communications, 2016,7:13713. DOI URL PMID
[10]	LI G D, AYDEMIR U, WOOD M, et al. Ideal strength and deformation mechanism in high-efficiency thermoelectric SnSe. Chemistry of Materials, 2017,29:2382-2389. DOI URL
[11]	FU J, SU X, XIE H, et al. Understanding the combustion process for the synthesis of mechanically robust SnSe thermoelectrics. Nano Energy, 2018,44:53-62.
[12]	CHEN Z G, SHI X L, ZHAO L D, et al. High-performance SnSe thermoelectric materials: progress and future challenge. Progress in Materials Science, 2018,97:283-346.
[13]	WU D, WU L J, ZHAO L D, et al. Direct observation of vast off-stoichiometric defects in single crystalline SnSe. Nano Energy, 2017,35:321-330.
[14]	JIN M, XU J Y, LI X H, et al. Microhardness and fracture toughness of <111> oriented PZNT single crystal. Materials Science and Engineering A, 2008,472(1):353-357. DOI URL
[15]	CHU F, ZHANG Q, ZHOU Z, et al. Enhanced thermoelectric and mechanical properties of Na-doped polycrystalline SnSe thermoelectric materials via CNTs dispersion. J. Alloys Compd., 2018,741:756-764. DOI URL
[16]	XU Z J, HU L P, YING P J, et al. Enhanced thermoelectric and mechanical properties of zone melted p-type (Bi, Sb)₂Te₃ thermoelectric materials by hot deformation. Acta Materialia, 2015,84:385-392.
[17]	REN F, HALL B D, NI J E, et al. Mechanical Characterization of PbTe-based Thermoelectric Materials. Materials Research Society Symposium Proceedings, 2008,1044:121.
[18]	LIU Z, GAO W, MENG X, et al. Mechanical properties of nanostructured thermoelectric materials α-MgAgSb. Scripta Materialia, 2017,127:72-75. DOI URL
[19]	JIN M, XU J Y, SHI M L, et al. Mechanical properties anisotropy of PZNT93/7 single crystal. Journal of Physics D: Applied Physics, 2007,40(5):1473-1476. DOI URL
[20]	JIN M, FANG Y Z, SHEN H, et al. Mechanical property evaluation of GaAs crystal for solar cells. Chinese Physics Letters, 2011,28(8):086101. DOI URL
[21]	GUPTA V, BAMZAI K K, KOTRU P N, et al. Mechanical characteristics of flux-grown calcium titanate and nickel titanate crystals. Materials Chemistry & Physics, 2005,89:64-71.