Pb₇Bi₄Se₁₃: A Lillianite Homologue with Promising Thermoelectric Properties

Abstract

Pb(7)Bi(4)Se(13) crystallizes in the monoclinic space group C2/m (No. 12) with a = 13.991(3) Å, b = 4.262(2) Å, c = 23.432(5) Å, and β = 98.3(3)° at 300 K. In its three-dimensional structure, two NaCl-type layers A and B with respective thicknesses N(1) = 5 and N(2) = 4 [N = number of edge-sharing (Pb/Bi)Se6 octahedra along the central diagonal] are arranged along the c axis in such a way that the bridging monocapped trigonal prisms, PbSe7, are located on a pseudomirror plane parallel to (001). This complex atomic-scale structure results in a remarkably low thermal conductivity (∼0.33 W m(-1) K(-1) at 300 K). Electronic structure calculations and diffuse-reflectance measurements indicate that Pb(7)Bi(4)Se(13) is a narrow-gap semiconductor with an indirect band gap of 0.23 eV. Multiple peaks and valleys were observed near the band edges, suggesting that Pb(7)Bi(4)Se(13) is a promising compound for both n- and p-type doping. Electronic-transport data on the as-grown material reveal an n-type degenerate semiconducting behavior with a large thermopower (∼-160 μV K(-1) at 300 K) and a relatively low electrical resistivity. The inherently low thermal conductivity of Pb(7)Bi(4)Se(13) and its tunable electronic properties point to a high thermoelectric figure of merit for properly optimized samples.

Hierarchical Architecturing for Layered Thermoelectric Sulfides and Chalcogenides

“…The two layers are stacked alternately along the c -axis, resulting in a three-dimensional structure with varying thicknesses that form different members in the homology. The thermoelectric properties of homologous compounds can be tuned by modifying the size and shape of the structural module(s); therefore, the homologous compounds are good platforms for developing new thermoelectric materials [34,94,98,99,100,101,102,103,104,105,106,107,108,109]. …”

“…Figure 10 shows the κ lat , ZT , and crystal structure of CsBi 4 Te 6 , a member of the Cs 4 [Bi 2 n +4 Te 3 n +6 ] homologous series [99,102]; SnBi 2 Te 4 , a member of the [SnTe] n [Bi 2 Te 3 ] m homologous series [106,107]; Pb 5 Bi 6 Se 14 , a member of the cannizzarite homologous series [34]; PbBi 2 S 4 , a member of the galenobismuthite homologous series [34]; and Pb 7 Bi 4 Se 13 , a member of lillianite homologous series [109]. CsBi 4 Te 6 and SnBi 2 Te 4 show p -type behavior, while Pb 5 Bi 6 Se 14 , PbBi 2 S 4 , and Pb 7 Bi 4 Se 13 show n -type behavior.…”

Supramolecular Assemblies in Pb(II) Complexes with Hydrazido-Based Ligands

“…Consequently, it has been used for the preparation of new hybrid inorganic-organic compounds, polymers and complexes [1][2][3][4]. It is well-known that the utilization of lead(II) has negative implications related to environmental issues and health; however, it used for the synthesis of materials with interesting properties like semiconductors, NLO (non-linear optical) and ferroelectric materials [5][6][7][8]. In fact, nowadays the technical, economic and social relevance of Pb is beyond all doubt [9].…”

Crystal Structure Determination of Ag3Pb4Bi11Se22 by Microfocussed Synchrotron Radiation

“…However, these multinary sulfides lack sufficient electrical conductivity. [3] As exemplified by Pb 7 Bi 4 Se 13 , moving from sulfur to selenium results in a reasonable electrical conductivity combined with a rather high Seebeck coefficient and a further reduced phononic part of the thermal conductivity, leading to ZT values of up to 0.9 at 775 K. [4] The structure is derived from that of the mineral lillianite and consists of a sequence of tilted distorted NaCl-type slabs of different sizes. [5] These slabs are interconnected by a cation position with capped trigonal prismatic coordination.…”