Solution processable copper halide based inorganic-organic hybrid materials for photoluminescence related applications
Creators: name: Hei, Xiuze
Publisher: name: No Publisher Supplied
Year: 2023

description: Crystalline inorganic-organic hybrid semiconductor materials have continued to attract increasing attention due to their potential in optoelectronic applications, including but not limited to, photovoltaics, light-emitting diodes, and photodetectors. These materials are made of inorganic and organic motifs and therefore possess a wide range of interesting properties inherited from both components. Moreover, synergetic features result from the interplay of two components are often observed, which are extrinsic to each counterpart alone. As an important and promising class of the inorganic-organic hybrid materials, copper(I) halide based hybrid semiconductors have shown substantial promise in photoluminescence (PL) related applications due to their facile synthesis, non-toxic nature, excellent optical properties and structural diversity. Since the first report on the Cu4I4 cubane cluster based hybrid material in 1976, great effort has been made to design and synthesize novel functional hybrid semiconductors based on copper halides. However, it was not until recently that their potential as rare-earth-element (REE) free light-emitting materials has been fully revealed. Designing novel structures with desired properties and understanding their structure-property relationship have now become a very hot topic and studied extensively by the scientific community.While high photoluminescence quantum yields (PLQYs) have been achieved for CuX(L) hybrids constructed of both charge-neutral inorganic CuX modules and organic ligands, which form coordinative bonds, the major drawbacks of these materials include poor solution processability and/or structural instability. To address these issues, our group developed a synthetic approach to form hybrid structures consisting of covalently bonded cation–anion pairs, noted as All-In-One (AIO) structures. The integration of the coordination bonds and ionic bonds in a single crystal lattice allows the AIO structures to inherit all the beneficial features from the two constituents, such as optical tunability, enhanced chemical and thermal stability, strong luminescence, and solution processability. These desirable features render the AIO structures as promising candidates for various applications. My research has been focusing on designing new AIO type CuX(L) hybrid semiconductors with desired optical and electrical properties, for possible use in solution-processed thin-film devices.On the other hand, in-depth study and understanding of the structural-property relationships in these materials is equally important and will be crucial in guiding the future efforts to further modify their structures and to enhance/optimize their properties. The effects of halogen substitution, ligand coordination modes, ligand hybridizations, as well as structural dimensionality on the optical properties of AIO type compounds were investigated by both experimental and theoretical methods, which have provided insight into the structure-property relationship of these inorganic-organic semiconductors.