The organic solid-state lightemitting materials have attracted more and more attention owing to their promising applications in displays,lasers and optical communications.In contrast to isolated molecule,there are var...The organic solid-state lightemitting materials have attracted more and more attention owing to their promising applications in displays,lasers and optical communications.In contrast to isolated molecule,there are various weak intermolecular interactions in organic solids that sometimes have a large impact on the excited-state properties and energy dissipation pathways,resulting in strong fluorescence/phosphorescence.It is increasingly necessary to reveal the luminescence mechanism of organic solids.Here,we briefly review how intermolecular interactions induce strong normal fluorescence,thermally activate delayed fluorescence and room-temperature phosphorescence in organic solids by examining changes in geometry,electronic structures,electron-vibration coupling and energy dissipation dynamics of the excited states from isolated to aggregated molecules.We hope that the review will contribute to an in-depth understanding of the excited state properties of organic solids and to the design of excellent solid-state light-emitting materials.展开更多
Unveiling the dependence of stability and luminescence properties on the size of organic aggregates is crucial for biomedical and optoelectronic applications.Taking the helical hexaphenylsilole(HPS)and planar 3-(2-cya...Unveiling the dependence of stability and luminescence properties on the size of organic aggregates is crucial for biomedical and optoelectronic applications.Taking the helical hexaphenylsilole(HPS)and planar 3-(2-cyano-2-phenylethenyl-Z)-NH-indole(CPEI)aggregates of different sizes as examples,their stability and luminescent properties are investigated using multiscale modeling and thermal vibration correlation function approach.The size of stable aggregates formed depends on the molecular shape,with the critical aggregate sizes of 2.62 nm(2 molecules)and 2.87 nm(10 molecules)for helical HPS and planar CPEI,respectively.Their critical sizes for luminescence are 2.99 nm(6 molecules)and 2.87 nm(10 molecules),respectively.For HPS aggregates,as the size increases the luminescence is blue-shifted and enhanced owing to denser molecular packing until the size is large enough(4.66 nm,20 molecules)the luminescence tends to remain unchanged;and thermal annealing makes these changesmore pronounced.In contrast,the luminescent properties of CPEI aggregates are insensitive to aggregate size and thermal annealing treatment.These findings provide dynamic insights into the AIE mechanism and invaluable guidance for optimizing the size of AIE-based nanoparticles in practical applications.展开更多
基金supported by the National Natural Science Foundation of China(No.21973099)。
文摘The organic solid-state lightemitting materials have attracted more and more attention owing to their promising applications in displays,lasers and optical communications.In contrast to isolated molecule,there are various weak intermolecular interactions in organic solids that sometimes have a large impact on the excited-state properties and energy dissipation pathways,resulting in strong fluorescence/phosphorescence.It is increasingly necessary to reveal the luminescence mechanism of organic solids.Here,we briefly review how intermolecular interactions induce strong normal fluorescence,thermally activate delayed fluorescence and room-temperature phosphorescence in organic solids by examining changes in geometry,electronic structures,electron-vibration coupling and energy dissipation dynamics of the excited states from isolated to aggregated molecules.We hope that the review will contribute to an in-depth understanding of the excited state properties of organic solids and to the design of excellent solid-state light-emitting materials.
基金supported by the National Natural Science Foundation of China(Grant Nos.22325305,22273105,21973099,22173006)the Information Plan of the Chinese Academy of Sciences(Grant No.CAS-WX2023PY-0103)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.E2E40307X2)Beijing Natural Science Foundation(Grant No.2222027).
文摘Unveiling the dependence of stability and luminescence properties on the size of organic aggregates is crucial for biomedical and optoelectronic applications.Taking the helical hexaphenylsilole(HPS)and planar 3-(2-cyano-2-phenylethenyl-Z)-NH-indole(CPEI)aggregates of different sizes as examples,their stability and luminescent properties are investigated using multiscale modeling and thermal vibration correlation function approach.The size of stable aggregates formed depends on the molecular shape,with the critical aggregate sizes of 2.62 nm(2 molecules)and 2.87 nm(10 molecules)for helical HPS and planar CPEI,respectively.Their critical sizes for luminescence are 2.99 nm(6 molecules)and 2.87 nm(10 molecules),respectively.For HPS aggregates,as the size increases the luminescence is blue-shifted and enhanced owing to denser molecular packing until the size is large enough(4.66 nm,20 molecules)the luminescence tends to remain unchanged;and thermal annealing makes these changesmore pronounced.In contrast,the luminescent properties of CPEI aggregates are insensitive to aggregate size and thermal annealing treatment.These findings provide dynamic insights into the AIE mechanism and invaluable guidance for optimizing the size of AIE-based nanoparticles in practical applications.
