BaZrS₃ – Single Crystals, Growth and Properties

Perovskite chalcogenide materials have gained increasing interest as potentially stable materials with promising optoelectronic properties owing to their structure type. These materials have the general formula of AMX₃ with A being a group II cation (i.e., Ca²⁺, Sr²⁺, or Ba²⁺), M a group IV transition metal (i.e., Ti⁴⁺, Zr⁴⁺, or Hf⁴⁺), and X a chalcogen anion (S²⁻ or Se²⁻). These materials have been known for a long time and attempts to prepare them have been made in many ways. Single crystals of this group of materials were prepared by the flux method. However, most of the data regarding structure and optoelectronic properties were determined on polycrystalline thin films (e. g. [1, 2]).<br/>BaZrS₃ as a representative of this class of materials crystallizes in the orthorhombic perovskite-type structure. For thin films of BaZrS₃ a band gap energy of 1.95eV [3] and 1.99eV [2], respectively, has been determined.<br/>Here we report on the growth of single crystals of BaZrS₃ and their crystal structure and optoelectronic properties compared to thin films. The BaZrS₃ crystals were grown by chemical vapor transport (CVT) using iodine as a transport agent. The resulting material and grown crystals were characterized by powder X-ray diffraction (XRD) and LeBail analysis of the diffraction pattern, as well as by single-crystal X-ray diffraction. The chemical composition of the crystals was determined by X-ray fluorescence. The band gap energy was determined from the diffuse reflectance measured by UV-VIS spectroscopy.<br/><b>Reference:</b><br/>[1] Ramanandan, S. P. et al., Journal of Physics: Energy 2023, 5, 014013<br/>[2] Marquez, J. A. et al., Journal of Physical Chemistry Letters 2021, 12, 2148<br/>[3] Nishigaki, Y. et al. Sol. RRL 2020, 4 (5), 1900555