Cs 3 Cu 4 In 2 Cl 13 Nanocrystals: A Perovskite-Related Structure with Inorganic Clusters at A Sites

• Published in: Inorganic chemistry 2020-01, Vol.59 (1), p.548-554
• Main Authors: Kaiukov, Roman, Almeida, Guilherme, Marras, Sergio, Dang, Zhiya, Baranov, Dmitry, Petralanda, Urko, Infante, Ivan, Mugnaioli, Enrico, Griesi, Andrea, De Trizio, Luca, Gemmi, Mauro, Manna, Liberato
• Format: Article
• Language: English
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.9b02834

An effort to synthesize the Cu(I) variant of a lead-free double perovskite isostructural with Cs AgInCl resulted in the formation of Cs Cu In Cl nanocrystals with an unusual structure, as revealed by single-nanocrystal three-dimensional electron diffraction. These nanocrystals adopt a A BX structure (K PtCl type, termed vacancy ordered perovskite) with tetrahedrally coordinated Cu(I) ions. In the structure, 25% of the A sites are occupied by [Cu Cl] clusters (75% by Cs ), and the B sites are occupied by In . Such a Cs Cu In Cl compound prepared at the nanoscale is not known in the bulk and is an example of a multinary metal halide with inorganic cluster cations residing in A sites. The stability of the compound was supported by density functional theory calculations that also revealed that its bandgap is direct but parity forbidden. The existence of the Cs Cu In Cl structure demonstrates that small inorganic cluster cations can occupy A sites in multinary metal halides.