New Strategy for Optimizing the Properties of Copper Halide Organic‐Inorganic Hybrid Lighting‐emitting Materials

Abstract

Copper(I) halide organic‐inorganic hybrid luminescent materials have many advantages, such as diverse structure, facile synthesis, high luminescent efficiency, tunable optical performance, etc., and show a broad application prospect in energy‐saving lighting, display and other fields. However, compared with commercial rare‐earth‐metal‐based phosphors, the reported hybrids generally suffer from poor stability and low luminescent efficiency, which are the bottleneck problem of their practical application. With the aim of developing high‐performance organic‐inorganic hybrid luminescent materials, a new synthesis strategy has been reported. This strategy can systematically design and synthesis copper(I) halide ionic hybrid structures by combining the covalent bonding and ionic bonding between inorganic and organic components into one structure, and use their synergistic effect to optimizing their properties. This design method is expected to develop high‐performance organic‐inorganic hybrid luminescent materials, promote the in‐depth understanding of this field, and provide new ideas for the optimization of other types of hybrid materials.

Self-Assembly of an Anionic [Cu5I8]3– Supramolecular Cluster Driven by Ion-Pair Interaction and Catalytic Properties

“…High-nuclearity coordination clusters have attracted extensive attention because of their structural diversity − and wide-ranged application prospects in the field of photoelectron devices, − electrical conductivity, metal–organic catalysis, and fluorescent sensing. − As a common aggregate of copper­(I) atoms coordinated with halide anions, cuprous iodide clusters exhibited a variety of molecular arrays with rich electronic structures, including neutral, cationic, and anionic [Cu x I y ] x − y coordination moieties. − In the neutral cuprous iodide cluster aggregates [CuI] x , uncharged organic/inorganic ligands can support and stabilize the [CuI] x cores via Cu–N, Cu–S, or Cu–P coordination interactions, − such as Cu 2 I 2 rhomboid dimers, − Cu 3 I 3 trimers, Cu 4 I 4 cubane tetramers, , Cu 6 I 6 staircase hexamers, − Cu 7 I 7 pinwheel heptamers, − Cu 8 I 8 staircase octamers, and so forth. In order to construct ionic cuprous iodide clusters with high nuclearity, some cationic heteroleptic ligands were developed and reacted with copper iodide salt. − Up to date, it has rarely been reported for anionic cuprous iodide clusters, such as [Cu 4 I 6 (TPP) 2 ]­(TPP = alkyl-tris­(2-pyridyl)­phosphonium halides), [Cu 6 I 7 ] − , [L 4 (Cu 3 I 4 ) 4 ] 8+ , and so on . Among these ionic cuprous iodide cluster systems, the [Cu x I y ] x − y coordination moieties with a highly nuclear nature were self-assembled as driven by the intramolecular electrostatic interaction from anion–cation pairs in the aggregation process. , However, the structural diversity is influenced by multiple factors, which increase the difficulty in the controlling synthesis of ionic cuprous iodide clusters. ,,− …”

Cubane Dimerization: Cu4 vs Cu8 Copper Iodide Clusters

“…To develop environmentally friendly and sustainable solid-state luminescent materials, intense research on materials free of rare earth and lead ions is currently being carried out. − Due to the accessibility of elemental copper and the remarkable photophysical properties of copper­(I) complexes, − Cu­(I)-based materials are especially interesting for the development of cost-effective emissive materials that also combine high efficiency with low toxicity. − Among the Cu­(I) compounds, the family of copper halides is characterized by a wide range of photophysical properties associated with large structural diversity. − In particular, copper iodide compounds display intense and stable photoluminescence properties, making them a relevant alternative to lead-based hybrid perovskites. − …”