Abstract
Metal chalcogenides underpin a wide variety of energy-related applications and are ideal systems for probing lattice dynamics and fundamental transport phenomena. Here we describe the synthesis and transport properties of CsAg5TeS2 and its solid solution CsAg5Te3-xSx (x = 1-2), new semiconductors with tunable band gaps ranging from 0.17 to 0.30 eV. CsAg5TeS2 has a fully ordered two-dimensional structure that includes a group of Ag atoms in a heteroleptic tetrahedral coordination geometry (AgTe2S2). Single-crystal X-ray diffraction indicates that the compounds crystallize in the tetragonal space group P4/mmm, while pair distribution function (PDF) analysis reveals off-centering at the heteroleptic Ag sites, signifying the lower-symmetry I4/mcm space group. The underlying disorder acts as a phonon-blocking mechanism that helps facilitate an ultralow lattice thermal conductivity below 0.40 W·m-1·K-1 at ∼300 K, highlighting the importance of local disorder in thermal transport. Density functional theory provides additional insight into the electronic and thermal properties of the materials, which are good candidates for p-type thermoelectrics.
| Original language | English |
|---|---|
| Pages (from-to) | 7245-7254 |
| Number of pages | 10 |
| Journal | Chemistry of Materials |
| Volume | 30 |
| Issue number | 20 |
| DOIs | |
| Publication status | Published - Oct 23 2018 |
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ASJC Scopus subject areas
- Chemistry(all)
- Chemical Engineering(all)
- Materials Chemistry
Cite this
Two-Dimensional CsAg5Te3- xSx Semiconductors : Multi-anion Chalcogenides with Dynamic Disorder and Ultralow Thermal Conductivity. / Hodges, James M.; Xia, Yi; Malliakas, Christos D.; Alexander, Grant C.B.; Chan, Maria K.Y.; Kanatzidis, Mercouri G.
In: Chemistry of Materials, Vol. 30, No. 20, 23.10.2018, p. 7245-7254.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Two-Dimensional CsAg5Te3- xSx Semiconductors
T2 - Multi-anion Chalcogenides with Dynamic Disorder and Ultralow Thermal Conductivity
AU - Hodges, James M.
AU - Xia, Yi
AU - Malliakas, Christos D.
AU - Alexander, Grant C.B.
AU - Chan, Maria K.Y.
AU - Kanatzidis, Mercouri G
PY - 2018/10/23
Y1 - 2018/10/23
N2 - Metal chalcogenides underpin a wide variety of energy-related applications and are ideal systems for probing lattice dynamics and fundamental transport phenomena. Here we describe the synthesis and transport properties of CsAg5TeS2 and its solid solution CsAg5Te3-xSx (x = 1-2), new semiconductors with tunable band gaps ranging from 0.17 to 0.30 eV. CsAg5TeS2 has a fully ordered two-dimensional structure that includes a group of Ag atoms in a heteroleptic tetrahedral coordination geometry (AgTe2S2). Single-crystal X-ray diffraction indicates that the compounds crystallize in the tetragonal space group P4/mmm, while pair distribution function (PDF) analysis reveals off-centering at the heteroleptic Ag sites, signifying the lower-symmetry I4/mcm space group. The underlying disorder acts as a phonon-blocking mechanism that helps facilitate an ultralow lattice thermal conductivity below 0.40 W·m-1·K-1 at ∼300 K, highlighting the importance of local disorder in thermal transport. Density functional theory provides additional insight into the electronic and thermal properties of the materials, which are good candidates for p-type thermoelectrics.
AB - Metal chalcogenides underpin a wide variety of energy-related applications and are ideal systems for probing lattice dynamics and fundamental transport phenomena. Here we describe the synthesis and transport properties of CsAg5TeS2 and its solid solution CsAg5Te3-xSx (x = 1-2), new semiconductors with tunable band gaps ranging from 0.17 to 0.30 eV. CsAg5TeS2 has a fully ordered two-dimensional structure that includes a group of Ag atoms in a heteroleptic tetrahedral coordination geometry (AgTe2S2). Single-crystal X-ray diffraction indicates that the compounds crystallize in the tetragonal space group P4/mmm, while pair distribution function (PDF) analysis reveals off-centering at the heteroleptic Ag sites, signifying the lower-symmetry I4/mcm space group. The underlying disorder acts as a phonon-blocking mechanism that helps facilitate an ultralow lattice thermal conductivity below 0.40 W·m-1·K-1 at ∼300 K, highlighting the importance of local disorder in thermal transport. Density functional theory provides additional insight into the electronic and thermal properties of the materials, which are good candidates for p-type thermoelectrics.
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UR - http://www.scopus.com/inward/citedby.url?scp=85054629976&partnerID=8YFLogxK
U2 - 10.1021/acs.chemmater.8b03306
DO - 10.1021/acs.chemmater.8b03306
M3 - Article
AN - SCOPUS:85054629976
VL - 30
SP - 7245
EP - 7254
JO - Chemistry of Materials
JF - Chemistry of Materials
SN - 0897-4756
IS - 20
ER -