Synthesis of Hydride-Doped Perovskite Stannate with Visible Light Absorption Capability

Masashi Nakamura; Hirofumi Akamatsu; Kotaro Fujii; Yusuke Nambu; Yoichi Ikeda; Tomoki Kanazawa; Shunsuke Nozawa; Masatomo Yashima; Katsuro Hayashi; Kazuhiko Maeda

doi:10.1021/acs.inorgchem.2c00398

Synthesis of Hydride-Doped Perovskite Stannate with Visible Light Absorption Capability

Inorg Chem. 2022 May 2;61(17):6584-6593. doi: 10.1021/acs.inorgchem.2c00398. Epub 2022 Apr 17.

Authors

Masashi Nakamura^{1

2}, Hirofumi Akamatsu³, Kotaro Fujii¹, Yusuke Nambu^{4

5

6}, Yoichi Ikeda⁴, Tomoki Kanazawa⁷, Shunsuke Nozawa⁷, Masatomo Yashima¹, Katsuro Hayashi³, Kazuhiko Maeda¹

Affiliations

¹ Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1-NE-2 Ookayama, Meguro-ku, Tokyo 152-8551, Japan.
² Konoshima Chemical Co., Ltd., 80 Koda, Takuma, Mitoyo, Kagawa 769-1103, Japan.
³ Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
⁴ Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan.
⁵ FOREST, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan.
⁶ Organization for Advanced Studies, Tohoku University, Sendai 980-8577, Japan.
⁷ Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801, Japan.

PMID: 35430816
DOI: 10.1021/acs.inorgchem.2c00398

Abstract

Narrow-gap semiconductors with visible light absorption capability have attracted attention as photofunctional materials. H^--doped BaSn_0.7Y_0.3O_3-δ containing Sn(II) species was recently reported to absorb visible light up to 600 nm, which represents the first demonstration of oxyhydride-based visible-light-absorbers. In the present study, a more detailed investigation was made to obtain information on the synthesis and properties of H^--doped perovskite-type stannate with respect to the A-site cation of the material and the preparation conditions. H^--doped ASn_0.7Y_0.3O_3-δ (A = Ba, Ba_0.5Sr_0.5, and Sr) obtained by the reaction of ASn_0.7Y_0.3O_3-δ precursors with CaH₂ at 773 K under vacuum conditions was shown to have almost the same bandgap (ca. 2.1 eV), regardless of the A-site cation. Physicochemical measurements and theoretical calculations revealed that the identical bandgaps of H^--doped ASn_0.7Y_0.3O_3-δ are due to the simultaneous shift of the midgap states composed of Sn²⁺ with the conduction band minimum. Experimental results also indicated that the appropriate preparation conditions with respect to Y³⁺-substitution and the temperature for the synthesis of the ASn_0.7Y_0.3O_3-δ precursors were essential to obtain H^--doped products that have a low density of defects.