Compositional Effects and Electron Lone‐pair Distortions in Doped Bournonites

Abstract

Bornite materials are naturally occurring systems composed of earth-abundant constituents. Bournonite, a representative of this class of materials, is of interest for thermoelectric applications due to its inherently low thermal conductivity, which has been attributed to the lattice distortions due to stereochemically active electron lone pair distributions. In this computational and experimental study, we present analyses of the lattice structure, electron and phonon dynamics, and charge localization and transfer properties for undoped and Ni and Zn doped bournonites. The results from our simulations reveal complex relations between bond length and bond angle characteristics, chemical bonding, and charge transfer upon doping. Analysis of the experimental results indicate that a microscopic description for bournonite and its doped compositions is necessary for a complete understanding of these materials, as well as for effective control of the transport properties for targeted applications.

Synthesis, Crystal Structure, and Physical Properties of BaSnS2

“…Lone-pair electrons, required to form the trigonal pyramid in BaSnS 2 , as well as trigonal bipyramidal local environments in the case of other chalcogenide materials, can be sources of low-frequency modes. [42][43][44][45][46] Theoretical investigations would be useful in elucidating further insight.…”

Thermal Properties of the Quaternary Chalcogenide BaCdSnSe4

“…For certain quaternary chalcogenides, a low thermal conductivity can be related to their bonding and crystal structures. [ 10–16 ]…”

“…For certain quaternary chalcogenides, a low thermal conductivity can be related to their bonding and crystal structures. [10][11][12][13][14][15][16] Wide-bandgap quaternary chalcogenides continue to be of interest for frequency conversion in mid-to far-infrared laser applications. [4] One aspect of the bonding and structural arrangement in these materials is the coordination preferences of the metals with the chalcogen, with threefold, fourfold, and sometimes fivefold coordination in the crystal structure.…”

Molecular Precursor Route to Bournonite (CuPbSbS3) Thin Films and Powders

“…We have also demonstrated that mixing of metal dithiocarbamate precursors allows the spray-coating of metal sulfide thin films including examples of binary (1 precursor), ternary (2 precursors), and quaternary (3 precursors) metal sulfide materials ( n = 18) . For the synthesis of bournonite, this mixed precursor approach could be used to easily explore off-stoichiometric materials and doped and alloyed derivatives, which are known or predicted to exist. , Second, molecular precursors tend to form kinetic products due to the rapid decomposition and ultimate crystallization steps involved, which could sidestep the potential formation of PbS and Sb 2 S 3 side products. , We have recently observed the formation of kinetic products, for example, in the formation of molybdenum–tungsten trioxide alloys . In this paper, we explore for the first time the use of metal dithiocarbamate complexes as precursors toward bournonite.…”

“… 26 For the synthesis of bournonite, this mixed precursor approach could be used to easily explore off-stoichiometric materials and doped and alloyed derivatives, which are known or predicted to exist. 24 , 27 Second, molecular precursors tend to form kinetic products due to the rapid decomposition and ultimate crystallization steps involved, which could sidestep the potential formation of PbS and Sb 2 S 3 side products. 18 , 24 We have recently observed the formation of kinetic products, for example, in the formation of molybdenum–tungsten trioxide alloys.…”