In recent years, a large number of studies on LED materials and devices have made it possible to replace traditional light sources in the field of solid-state white light illumination and greatly reduce global lighting energy consumption. One of the key studies in the field of white LEDs today is to develop single-component Phosphors. Only a few two-dimensional perovskite-based lead halide materials based on (110) facets exhibit unique eigen-broadened white light emission properties that can be controlled by the macroscopic crystal structure design of the luminescent properties of the material However, at present, the luminescent quantum yield of such lead halide perovskite materials is low and the stability is poor, which greatly limits the practical application of such materials.
Professor Fei Honghan of our school of chemistry science and engineering is devoted to the research in the field of modification and heterogeneous catalysis of metal organic framework, and has been actively researching and solving the above problems. Recently, the group synthesized the anionic structure-directing agent A novel class of novel structured inorganic lead halides is a two-dimensional layered lattice material exhibiting a broad spectral emission with large Stokes shift that covers almost the entire visible range with a fluorescence absolute quantum yield of up to about 11.8%. These corrugated cationic lead halides lead to distorted metal centers in the two-dimensional crystal plane, leading to electron-phonon coupling in the distorted lattice and generating a large number of self-trapped excitons.The study of the luminescence mechanism shows that the two- The stretching vibration of Pb-Cl bonds in the surface at room temperature overcomes the potential barrier for electrons to change from a free state to a trapped state. More importantly, these cationic two-dimensional inorganic lead halide materials exhibit excellent chemical stability And photothermal stability, the luminescence intensity remained almost unchanged after irradiation with UV lamp (4 W, 365 nm) for 30 days in the atmospheric environment at room temperature.Therefore, the initial solution of this kind of material A lead halide perovskite material more sensitive to shortcomings in the air environment, and its luminescence properties can be further improved by regulation of the crystal structure, it has a broad application prospect.
Recently, the related research results published in the international authoritative chemical journal Angew. Chem. Int. Ed. (Intrinsic Broadband White-Light Emission from Ultrastable, Cationic Lead Halide Layered Materials' . 2017, 56, 14411-14416). The group is the only one completed. Prof. Fei Honghan is the author of a separate communication. The undergraduates Zhuang Zewen and PhD Candidate Peng Chengdong are co-authors.
Professor Fei Honghan joined the Faculty of Chemistry (now Faculty of Chemistry and Engineering) and the Institute of Advanced Studies of Tongji University in 2015 as a distinguished researcher and was selected into the National Youth Thousand Talents Program in 2016 as a Distinguished Professor of Tongji University. Science Fund Project (51772217), the Youth Fund Project (21501136) and the start-up funds of the young people such as fund support.
