Recently, researchers led by Dr. Kaifeng Wu and Associate Researcher Pengfei Cheng from the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, have made new progress in the study of phosphorescence dynamics in metal halides. They have revealed the role of doping in modulating the intrinsic defect properties of metal halides, leading to the realization of blue long-lasting phosphorescence in all-inorganic metal halides. This research has been published in "Applied Chemistry Germany."
Blue Long-Persistent Luminescence Schematic. Image provided by Dalian Institute of Chemical Physics.
Persistent luminescent materials can continue to emit light after excitation stops, holding great potential in anti-counterfeiting, information storage, and bioimaging. In recent years, organic-inorganic hybrid metal halide materials with persistent luminescence properties have garnered attention due to their low cost, processability in solution, and tunable optical properties. However, their luminescence mainly originates from the triplet excitons of organic components, facing challenges such as short duration and sensitivity to air and temperature. In contrast, an all-inorganic metal halide can achieve longer persistent luminescence and higher stability, but the luminescence color is mainly determined by dopants and has not yet reached the blue spectral range.
In this study, the team introduced Cu(I) into all-inorganic Rb2AgBr3 single crystals and achieved ultra-long blue persistent luminescence by controlling its intrinsic defect properties. The research shows that the introduced cuprous ions promote the formation of bromine vacancies, which capture and store charges for an extended period, leading to bright and long-lasting luminescence after excitation stops. Furthermore, this doping strategy resulted in the formation of three luminescent centers in the crystal, where cascade energy transfer between different luminescent centers generated white light emission with a quantum yield of approximately 91.3% and extended the fluorescence spectrum to the near-infrared region. The combination of blue long-persistent luminescence and bright broadband fluorescence demonstrates significant potential applications of this material in solid-state lighting, night vision, and intelligent anti-counterfeiting.
This work achieved synergistic control over the fluorescence and persistent luminescence properties of metal halides, offering new insights for designing multifunctional metal halide materials.
Related paper information: https://doi.org/10.1002/anie.202403927
