Bournonite PbCuSbS₃: Stereochemically Active Lone‐Pair Electrons that Induce Low Thermal Conductivity

Abstract

An understanding of the structural features and bonding of a particular material, and the properties these features impart on its physical characteristics, is essential in the search for new systems that are of technological interest. For several relevant applications, the design or discovery of low thermal conductivity materials is of great importance. We report on the synthesis, crystal structure, thermal conductivity, and electronic-structure calculations of one such material, PbCuSbS3 . Our analysis is presented in terms of a comparative study with Sb2 S3 , from which PbCuSbS3 can be derived through cation substitution. The measured low thermal conductivity of PbCuSbS3 is explained by the distortive environment of the Pb and Sb atoms from the stereochemically active lone-pair s(2) electrons and their pronounced repulsive interaction. Our investigation suggests a general approach for the design of materials for phase-change-memory, thermal-barrier, thermal-rectification and thermoelectric applications, as well as other functions for which low thermal conductivity is purposefully sought.

Enhancement of Solar Energy Absorption and Optoelectronic Properties of SrCuSbS3 by Lead Doping

“…Two nearest chains are connected by the [SbS 3 ] 3− triangular pyramids. The similar connection is also presented in the natural bournonite (PbCuSbS 3 : Pn 2 1 m , a = 7.811 Å, b = 8.152 Å, c = 8.704 Å) . However, the [CuS 3 ] 5− one‐dimensional chains are much regular in PbCuSbS 3 than that in SrCuSbS 3 .…”

“…The size‐dependent band gaps of lead chalcogenide quantum dots inspire us, and let us think that we can incorporate Pb 2+ ions into the CAS materials. However, the known PbCuSbS 3 is not suitable for photoelectric application due to its small band gap (<1 eV) . Therefore, partially replace Sr 2+ by Pb 2+ is reasonable to produce new CAS materials with suitable band gaps.…”

High Performance Thermoelectric Materials: Progress and Their Applications

“…[75,76] Cu 2 Se-and SnSe-based materials were newly realized as excellent TE materials because of the Cu ion liquid-like behavior [42] in Cu 2 Se, and ultralow κ L of SnSe due to the anharmonic scattering mechanism coming from the lone s-pair electrons, [47] which have been recognized in many chalcogenides. [77][78][79] Meanwhile, huge efforts have been made to promote the TE materials in commercial applications. [16,18] Indeed, in recent years, the development of nontoxic, low-cost [80,81] TE materials has been considered as key for future commercial applications, so that many promising TE materials have been explored due to their nontoxicity and earth abundancy, such as Cu-based materials including Cu 2 CdSnSe 4 , [80] Cu 2 ZnGeSe 4 , [81] Cu 12 Sb 4 S 13 , [82] BiCuSeO, [83] and lead-free SnTe.…”

The Origin of Ultralow Thermal Conductivity in InTe: Lone‐Pair‐Induced Anharmonic Rattling

“…[12,13] Theorigin of lattice anharmonicity and the ensuing ultralow k L in the I-V-VI 2 chalcogenides,such as AgSbSe 2 , [14] AgBiSe 2 , [15] AgBiS 2 , [16] and AgBiSeS, [17] has been traced to the electrostatic repulsion between the stereochemically active ns 2 lone pair of Group 15 cations and the valence p-orbital of Group 16 anions.Intrinsically low k L has also been evidenced in Cu 12 Sb 4 S 13 [18] and PbCuSbS 3 [19] due to the bond anharmonicity caused by stereochemically active 5s 2 lone pair of Sb.T he deformation of weak multicenter bonds in an electron-poor CdSb has been recently shown to cause lattice anharmonicity and thereby al ow k L . [12,13] Theorigin of lattice anharmonicity and the ensuing ultralow k L in the I-V-VI 2 chalcogenides,such as AgSbSe 2 , [14] AgBiSe 2 , [15] AgBiS 2 , [16] and AgBiSeS, [17] has been traced to the electrostatic repulsion between the stereochemically active ns 2 lone pair of Group 15 cations and the valence p-orbital of Group 16 anions.Intrinsically low k L has also been evidenced in Cu 12 Sb 4 S 13 [18] and PbCuSbS 3 [19] due to the bond anharmonicity caused by stereochemically active 5s 2 lone pair of Sb.T he deformation of weak multicenter bonds in an electron-poor CdSb has been recently shown to cause lattice anharmonicity and thereby al ow k L .…”