Abstract
Cs2Hg3S4 was synthesized by slowly cooling a melted stoichiometric mixture of Hg and Cs2S4. Cs2Hg3S4 crystallizes in the Ibam spacegroup with a = 6.278(1) Å, b = 11.601(2) Å, and c = 14.431(3)Å; dcalc = 6.29 g/cm3. Its crystal structure consists of straight chains of [Hg3S4]n2n- that engage in side-by-side weak bonding interactions forming layers and are charge balanced by Cs+ cations. The thermal stability of this compound was investigated with differential thermal analysis and temperature dependent in situ synchrotron powder diffraction. The thermal expansion coefficients of the a, b, and c axes were assessed at 1.56 × 10-5, 2.79 × 10-5, and 3.04 × 10-5 K-1, respectively. Large single-crystals up to ∼5 cm in length and ∼1 cm in diameter were grown using a vertical Bridgman method. Electrical conductivity and photoconductivity measurements on naturally cleaved crystals of Cs2Hg3S4 gave resistivity ρ of ≥108 ω·cm and carrier mobility-lifetime (μδ) products of 4.2 × 10-4 and 5.82 × 10-5 cm2 V-1 for electrons and holes, respectively. Cs2Hg3S4 is a semiconductor with a bandgap Eg ∼ 2.8 eV and exhibits photoluminescence (PL) at low temperature. Electronic band structure calculations within the density functional theory (DFT) framework employing the nonlocal hybrid functional within Heyd-Scuseria-Ernzerhof (HSE) formalism indicate a direct bandgap of 2.81 eV at. The theoretical calculations show that the conduction band minimum has a highly dispersive and relatively isotropic mercury-based s-orbital-like character while the valence band maximum features a much less dispersive and more anisotropic sulfur orbital-based band.
| Original language | English |
|---|---|
| Pages (from-to) | 370-378 |
| Number of pages | 9 |
| Journal | Chemistry of Materials |
| Volume | 27 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Jan 13 2015 |
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ASJC Scopus subject areas
- Materials Chemistry
- Chemical Engineering(all)
- Chemistry(all)
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Cs2Hg3S4 : A low-dimensional direct bandgap semiconductor. / Islam, Saiful M.; Vanishri, S.; Li, Hao; Stoumpos, Constantinos C.; Peters, John A.; Sebastian, Maria; Liu, Zhifu; Wang, Shichao; Haynes, Alyssa S.; Im, Jino; Freeman, Arthur J; Wessels, Bruce; Kanatzidis, Mercouri G.
In: Chemistry of Materials, Vol. 27, No. 1, 13.01.2015, p. 370-378.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Cs2Hg3S4
T2 - A low-dimensional direct bandgap semiconductor
AU - Islam, Saiful M.
AU - Vanishri, S.
AU - Li, Hao
AU - Stoumpos, Constantinos C.
AU - Peters, John A.
AU - Sebastian, Maria
AU - Liu, Zhifu
AU - Wang, Shichao
AU - Haynes, Alyssa S.
AU - Im, Jino
AU - Freeman, Arthur J
AU - Wessels, Bruce
AU - Kanatzidis, Mercouri G
PY - 2015/1/13
Y1 - 2015/1/13
N2 - Cs2Hg3S4 was synthesized by slowly cooling a melted stoichiometric mixture of Hg and Cs2S4. Cs2Hg3S4 crystallizes in the Ibam spacegroup with a = 6.278(1) Å, b = 11.601(2) Å, and c = 14.431(3)Å; dcalc = 6.29 g/cm3. Its crystal structure consists of straight chains of [Hg3S4]n2n- that engage in side-by-side weak bonding interactions forming layers and are charge balanced by Cs+ cations. The thermal stability of this compound was investigated with differential thermal analysis and temperature dependent in situ synchrotron powder diffraction. The thermal expansion coefficients of the a, b, and c axes were assessed at 1.56 × 10-5, 2.79 × 10-5, and 3.04 × 10-5 K-1, respectively. Large single-crystals up to ∼5 cm in length and ∼1 cm in diameter were grown using a vertical Bridgman method. Electrical conductivity and photoconductivity measurements on naturally cleaved crystals of Cs2Hg3S4 gave resistivity ρ of ≥108 ω·cm and carrier mobility-lifetime (μδ) products of 4.2 × 10-4 and 5.82 × 10-5 cm2 V-1 for electrons and holes, respectively. Cs2Hg3S4 is a semiconductor with a bandgap Eg ∼ 2.8 eV and exhibits photoluminescence (PL) at low temperature. Electronic band structure calculations within the density functional theory (DFT) framework employing the nonlocal hybrid functional within Heyd-Scuseria-Ernzerhof (HSE) formalism indicate a direct bandgap of 2.81 eV at. The theoretical calculations show that the conduction band minimum has a highly dispersive and relatively isotropic mercury-based s-orbital-like character while the valence band maximum features a much less dispersive and more anisotropic sulfur orbital-based band.
AB - Cs2Hg3S4 was synthesized by slowly cooling a melted stoichiometric mixture of Hg and Cs2S4. Cs2Hg3S4 crystallizes in the Ibam spacegroup with a = 6.278(1) Å, b = 11.601(2) Å, and c = 14.431(3)Å; dcalc = 6.29 g/cm3. Its crystal structure consists of straight chains of [Hg3S4]n2n- that engage in side-by-side weak bonding interactions forming layers and are charge balanced by Cs+ cations. The thermal stability of this compound was investigated with differential thermal analysis and temperature dependent in situ synchrotron powder diffraction. The thermal expansion coefficients of the a, b, and c axes were assessed at 1.56 × 10-5, 2.79 × 10-5, and 3.04 × 10-5 K-1, respectively. Large single-crystals up to ∼5 cm in length and ∼1 cm in diameter were grown using a vertical Bridgman method. Electrical conductivity and photoconductivity measurements on naturally cleaved crystals of Cs2Hg3S4 gave resistivity ρ of ≥108 ω·cm and carrier mobility-lifetime (μδ) products of 4.2 × 10-4 and 5.82 × 10-5 cm2 V-1 for electrons and holes, respectively. Cs2Hg3S4 is a semiconductor with a bandgap Eg ∼ 2.8 eV and exhibits photoluminescence (PL) at low temperature. Electronic band structure calculations within the density functional theory (DFT) framework employing the nonlocal hybrid functional within Heyd-Scuseria-Ernzerhof (HSE) formalism indicate a direct bandgap of 2.81 eV at. The theoretical calculations show that the conduction band minimum has a highly dispersive and relatively isotropic mercury-based s-orbital-like character while the valence band maximum features a much less dispersive and more anisotropic sulfur orbital-based band.
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U2 - 10.1021/cm504089r
DO - 10.1021/cm504089r
M3 - Article
AN - SCOPUS:84921395662
VL - 27
SP - 370
EP - 378
JO - Chemistry of Materials
JF - Chemistry of Materials
SN - 0897-4756
IS - 1
ER -