Fabrication Techniques of Group 15 Ternary Chalcohalide Nanomaterials

Nanocrystals of Lead Chalcohalides: A Series of Kinetically Trapped Metastable Nanostructures

“…Over the past decade, lead chalcogenides first and lead-halide perovskites later have been among the cornerstone materials in nanocrystal (NC) research. − Nowadays, many fundamental questions on these materials have been answered, and as interest in them is progressively shifting toward their applications, the quest for a new generation of inorganic NCs with appealing optoelectronic properties is becoming more compelling. An interesting class of compounds, which has hardly been explored on the nanoscale to date, is that of metal chalcohalides. − These materials offer a rich solid-state chemistry and structural diversity, , and they have proven to be useful for applications ranging from solar energy conversion to thermoelectrics, hard radiation detection, and superconductivity. − Among them, lead chalcohalides have been investigated in the past, up to the complete determination of the atmospheric pressure PbY–PbX 2 binary phase diagrams (Y = S, Se; X = Cl, Br, I), a search that led to the discovery and structural characterization of two stable (Pb 5 S 2 I 6 and Pb 7 S 2 Br 10 ) as well as some metastable chalcohalide structures (Pb 4 SCl 6 and Pb 4 SeBr 6 ). , For the PbS–PbBr 2 system, a few additional tentative stoichiometries have been identified. − In various works, different compositions such as (PbBr) 2 S, , “2PbS–PbCl 2 ”, and “2PbS–PbBr 2 ” , have been reported and even partially characterized, with Rabenau et al demonstrating that “2PbS–PbBr 2 ” thermally decomposes into a mixture of Pb 7 S 2 Br 10 and PbS . However, in the case of those latter phases the crystal structures were not determined, therefore precluding further investigations and leaving the door open to the possibility of identifying new lead chalcohalides.…”

Emerging Chalcohalide Materials for Energy Applications

“…The extensive developments in chalcohalide materials bring a necessity to review chalcohalides focusing on the materials design, their properties, film fabrication, and device fabrication while providing a perspective on future directions and potential applications in energy devices (Scheme ). The synthesis and applications of Bi- and Sb-based chalcohalide materials have been previously discussed as a part of dedicated book chapters − and reviews − as well as a brief overview of their potential in solar cell devices. − …”