TY - JOUR
T1 - Facile room temperature solventless synthesis of high thermoelectric performance Ag2Se
T2 - Via a dissociative adsorption reaction
AU - Yang, Dongwang
AU - Su, Xianli
AU - Meng, Fanchen
AU - Wang, Si
AU - Yan, Yonggao
AU - Yang, Jihui
AU - He, Jian
AU - Zhang, Qingjie
AU - Uher, Ctirad
AU - Kanatzidis, Mercouri G.
AU - Tang, Xinfeng
N1 - Funding Information:
We acknowledge support from the National Basic Research Program of China (973 program) under project 2013CB632502, the fundamental research funds for central campus (2015-III-061-061), the Natural Science Foundation of China (grant no. 51402222, 51172174, 51521001, and 51401153) and the 111 project of China (grant no. B07040). C.U. acknowledges support from the CERC-CVC, the joint U.S.–China Program supported by the U.S. Department of Energy under the award number DE-PI0000012 in verication of high temperature transport property measurements. F.M. and J.H. acknowledge support from the NSF DMR 1307740. Besides, D.Y. is grateful to Meijun Yang, Xiaolei Nie and Xinya Yang for their help with EPMA and C80 in Materials Research and Test Center of WHUT. This work was supported in part by a grant by the U.S. Department of Energy, Office of Science, and Office of Basic Energy Sciences under award number DE-SC0001054 (X.S and M.G.K., sample synthesis and transport characterization).
Publisher Copyright:
© 2017 The Royal Society of Chemistry.
PY - 2017
Y1 - 2017
N2 - Simultaneous control of the stoichiometry, microstructure, and compositional homogeneity is a prerequisite for understanding the properties of Ag2Se. These are difficult to attain because of the highly mobile Ag+ ions above the superionic phase transition at 407 K. Here we report on a novel synthesis of well crystallized orthorhombic Ag2Se carried out at room temperature, which requires no expensive instrumentation, and yields a single-phase material in a very short time. Our facile reaction process is a self-sustaining room temperature synthesis driven by the dissociative adsorption of Se by Ag and promoted by stirring and intermittent grinding under ambient conditions. Systematic experimental and theoretical studies of chemical reactions between Ag and Q (Te, Se, and S) revealed that the reaction mechanism between Ag and Q is in line with the Hard Soft Acid Base (HSAB) scheme (rate order Ag2Te > Ag2Se > Ag2S). The low carrier concentration achieved ∼1018 cm-3 and the optimized weighted majority-to-minority carrier mobility ratio observed in the samples as corroborated by the state-of-the-art thermoelectric performance of ZT ∼1.2 at 390 K attest to the superiority of the synthesis route in yielding highly stoichiometric Ag2Se samples.
AB - Simultaneous control of the stoichiometry, microstructure, and compositional homogeneity is a prerequisite for understanding the properties of Ag2Se. These are difficult to attain because of the highly mobile Ag+ ions above the superionic phase transition at 407 K. Here we report on a novel synthesis of well crystallized orthorhombic Ag2Se carried out at room temperature, which requires no expensive instrumentation, and yields a single-phase material in a very short time. Our facile reaction process is a self-sustaining room temperature synthesis driven by the dissociative adsorption of Se by Ag and promoted by stirring and intermittent grinding under ambient conditions. Systematic experimental and theoretical studies of chemical reactions between Ag and Q (Te, Se, and S) revealed that the reaction mechanism between Ag and Q is in line with the Hard Soft Acid Base (HSAB) scheme (rate order Ag2Te > Ag2Se > Ag2S). The low carrier concentration achieved ∼1018 cm-3 and the optimized weighted majority-to-minority carrier mobility ratio observed in the samples as corroborated by the state-of-the-art thermoelectric performance of ZT ∼1.2 at 390 K attest to the superiority of the synthesis route in yielding highly stoichiometric Ag2Se samples.
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U2 - 10.1039/c7ta08726h
DO - 10.1039/c7ta08726h
M3 - Article
AN - SCOPUS:85034248519
SN - 2050-7488
VL - 5
SP - 23243
EP - 23251
JO - Journal of Materials Chemistry A
JF - Journal of Materials Chemistry A
IS - 44
ER -