Copper(I)-Based Highly Emissive All-Inorganic Rare-Earth Halide Clusters

Halide perovskites are of great interest because of their large potential for a broad range of applications, such as photovoltaics, light-emitting diodes, and photodetectors. However, currently the state-of-the-art highly emissive halide perovskite materials contain toxic lead ions, and the synthesis of color-stable efficient blue-emissive perovskite analogs remains challenging. The discovery of lead-free, non-toxic halide materials with efficient blue light emission is promising for practical light-emitting applications. Here, we have discovered a series of highly blue-emissive all-inorganic Cu(I)-containing rare-earth halide compounds in the solid state at room temperature. The Cu(I) ions in the compounds show a 3-coordination geometry with the halide ions and connect Sc-Cl octahedra to form clusters in alternating layers, which play a crucial role in the regulation of the electronic structure and emission properties of this series of rare-earth halide cluster compounds.