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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on BaHfS3 by Materials Project

BaHfS3 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ba2+ is bonded in a 9-coordinate geometry to eight S2- atoms. There are a spread of Ba–S bond distances ranging from 3.20–3.36 Å. Hf4+ is bonded to six S2- atoms to form edge-sharing HfS6 octahedra. There are a spread of Hf–S bond distances ranging from 2.44–2.63 Å. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a 5-coordinate geometry to three equivalent Ba2+ and two equivalent Hf4+ atoms. In the second S2- site, S2- is bonded in a 4-coordinate geometry to one Ba2+ and three equivalent Hf4+ atoms. In the third S2- site, S2- is bonded in a 1-coordinate geometry to four equivalent Ba2+ and one Hf4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on BaHfS3 by Materials Project

BaHfS3 is Orthorhombic Perovskite structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ba2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ba–S bond distances ranging from 3.20–3.41 Å. Hf4+ is bonded to six S2- atoms to form corner-sharing HfS6 octahedra. The corner-sharing octahedra tilt angles range from 18–22°. There are two shorter (2.53 Å) and four longer (2.54 Å) Hf–S bond lengths. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a 4-coordinate geometry to two equivalent Ba2+ and two equivalent Hf4+ atoms. In the second S2- site, S2- is bonded in a 5-coordinate geometry to three equivalent Ba2+ and two equivalent Hf4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Breaking Barriers in Chalcogenide Perovskite Synthesis: A Generalized Framework for Fabrication of BaMS 3 (M═Ti, Zr, Hf) Materials

Abstract Chalcogenide perovskites have garnered increasing attention as stable, non‐toxic alternatives to lead halide perovskites. However, their conventional synthesis at high temperatures (>1000 °C) has hindered widespread adoption. Recent studies have developed low‐to‐moderate temperature synthesis methods (<600 °C) using reactive precursors, yet a comprehensive understanding of the pivotal factors affecting reproducibility and repeatability remains elusive. This study delineates the critical factors in the low‐temperature synthesis of BaMS 3 (M═Zr, Hf, Ti) compounds and presents a generalized framework. Innovative approaches are developed for synthesizing BaMS 3 compounds using this framework involving organometallics for solution deposition. The molecular precursor routes, employing metal acetylacetonates to generate soluble metal–sulfur bonded complexes and metal–organic compounds to produce soluble metal‐thiolate, metal‐isothiocyanate, and metal‐trithiocarbonate species, are demonstrated to yield carbon‐free BaMS 3 . These methods have achieved the most contiguous films of BaZrS 3 and BaHfS 3 using solution deposition to date. Furthermore, a hybrid solution processing method involving stacking sputter‐deposited Zr and solution‐deposited BaS layers is employed to synthesize a contiguous, oxygen‐free BaZrS 3 film. The diffuse reflectance measurements indicate a direct bandgap of ≈ 1.85 eV for the BaZrS 3 films and ≈ 2.1 eV for the BaHfS 3 film under investigation.

25 ENERGY STORAGE↗