Quantitative\nScales for Haliphilicity of Metals: Tailoring\nthe Halide Affinity of Alkaline Earth Metals to Synthesize Chalcogenide\nPerovskite BaMS<sub>3</sub> (M = Zr, and Hf) and Cu<sub>2</sub>BaSnS<sub>4</sub>

Chalcogenide semiconductors, such\nas BaMS<sub>3</sub> (M = Zr and\nHf) and Cu<sub>2</sub>BaSnS<sub>4</sub>, have attracted growing interest\ndue to the constituent elements’ abundance and reported promising\nproperties. However, the synthesis of these alkaline earth-containing\nchalcogenides from commonly available metal halides has generally\nbeen unsuccessful and has traditionally relied on expensive organometallic\nprecursors or vacuum processing techniques, which hinder widespread\nresearch on these materials. In this study, we conducted thermodynamic\ncalculations and developed chloriphilicity and iodiphilicity scales\nfor various metals, leveraging their relative affinities for chlorine\nand iodine, respectively, compared to their corresponding metal sulfides.\nUtilizing these scales, we introduced a K<sub>2</sub>S–H<sub>2</sub>S system to address the affinity of alkaline earth metals\nfor chlorine and iodine. This approach enables the synthesis of these\nintriguing chalcogenide materials through solution-based methods using\nmetal chloride and metal iodide precursors. This system demonstrates\nremarkable efficacy for both sulfide and selenide semiconductors.