Synthesis of Sulfide Perovskites by Sulfurization with Boron Sulfides

Abstract

Chalcogenide perovskites (CPs), with the general composition ABX3, where A and B are metals and X = S and Se, have recently emerged as promising materials for application in photovoltaics. However, the development of CPs and their applications has been hindered by the limitations of available preparation methods. Here we present a new approach for the synthesis of CPs, based on the sulfurization of ternary and binary oxides or carbonates with in situ formed boron sulfides. In contrast to the previously described approaches, the method presented here uses chemically stable starting materials and yields pure-phase crystalline CPs within several hours, under low hazard conditions. CP yields over 95% are obtained at temperatures as low as 600 °C. The generality of the approach is demonstrated by the preparation of CPs with compositions BaZrS3, β-SrZrS3, BaHfS3, SrHfS3, and EuHfS3. Mechanistic insights about the formation of CPs are discussed.

Syntheses, Crystal Structures, and Electronic Structures of Quaternary Group IV-Selenide Semiconductors

“…Recent studies have also demonstrated that lowertemperature reactions involving the use of sulfurization agents, e.g., boron sulfides or elemental sulfur, can also be effective in reactions with ternary oxides or other precursors. 18,19 Beyond the perovskite-type chalcogenides, recent investigations have shown that group-IV chalcogenides forming in alternative structures can possess similar favorable optoelectronic properties. In metal selenides where the perovskite-type structure has yet to be obtained, synthetic attempts have instead yielded the Ba 8 M 2 Se 11 (Se 2 ) (M = Zr, Hf) and Ba 9 Hf 3 Se 14 (Se 2 ) structures.…”

How the Temperature and Composition Govern the Structure and Band Gap of Zr-Based Chalcogenide Perovskites: Insights from ML Accelerated AIMD

“…Recently, several new methods for the preparation of CPs under more moderate conditions have been reported. 15,16 Computational predictions also played a substantial role in the increased interest in developing CP materials. Recently, the density functional theory (DFT)-based high-throughput computational screening of varied compositions was performed to identify compounds that are thermodynamically stable and have electronic properties suitable for exploitation in photovoltaics and optoelectronics.…”

“…However, the toxicity of one of its key components, Pb, and the limited thermal and chemical stability of halide perovskites represent major challenges to their effective application. , Chalcogenide perovskites (CPs) have recently been recognized as a possible alternative with a similar electronic structure, better thermal and chemical stability compared to their halide counterparts, and generally lower toxicity. − Although chemical methods for the preparation of CPs are known for more than 60 years, − the development of practical applications of CPs has been slow because of the high temperatures and long reaction times required. Recently, several new methods for the preparation of CPs under more moderate conditions have been reported. , …”

Predicting Sulfur‐Rich Oxysulfide Perovskites for Water‐Splitting Applications Using Machine Learning

“…Especially, their applicability in solar cell applications is still unknown. Further, since both oxides and many of the respective sulfides (the extreme ends of this series) based perovskites have now been well studied, [22][23][24][25] it becomes even more important to understand the nature of oxysulfides with varying concentration of oxygen and sulfur, specifically when the compound is sulfur-rich, owing to the stability of sulfur-rich compounds. [26,27] It may thus be expected that the sulfur-rich oxysulfide perovskites may provide an optimal bandgap and a suitable stabilty that is being desired for the nextgeneration water-splitting devices.…”