Nearly Unity Quantum Yield Persistent Room‐Temperature Phosphorescence from Heavy Atom‐Free Rigid Inorganic/Organic Hybrid Frameworks

Abstract

Synergism between covalent and non-covalent bonds is employed to fix an organic phosphor guest in a rigid inorganic framework, simulating the stiffening effect seen in the glassy state and realizing efficient and ultralong roomtemperature phosphorescence (RTP). Twelve heavy-atom-free composites have been obtained through introducing arylboric or arylcarboxylic acid derivatives into the inorganic boric acid matrix by solid-phase synthesis. Owing to the stiffening effect of multiple bonds, all the composites show highly efficient and persistent RTP of guest molecules with a quantum yield ranging from 39.8 % to ca. 100 % and a lifetime up to 8.74 s, which results in a 55 s afterglow visible to the naked eye after exposure to a portable UV lamp. Interestingly, it is found that the substitution position and quantity of carboxyl in the guest have a great influence on the phosphorescent properties, and that the heavy-atom effect is invalid in such host-guest hybrid systems. The 100 g grade composite is easily prepared because of the solvent-free, green, and simple synthesis method. These results provide an important way for the development of RTP materials with ultrahigh quantum yield and ultralong lifetime, as well as their practical applications in the fields of anti-counterfeiting and information storage, among others.

Efficient blue TADF-type organic afterglow materialviaboric acid-assisted confinement

“…What make the BA matrix so specific is that the vacant p orbital on the boron atoms can attack π transitions on NFX, forming p–n–π* conjugate systems. 22,34 The system is effective to reduce the minimum unoccupied orbital energy level of NFX, as confirmed by the prompt PL spectra of NFX and BNFX under 77 K (Fig. S10, ESI†).…”

“…In addition, it is more challenging to develop blue afterglow materials because of the difficulties in populating and stabilizing excitons at relatively high-lying triplet excited state, although blue/deep blue emissive materials are the essential core elements for achieving solid-state lighting and full-color display. 13,20–23…”

“…In addition, it is more challenging to develop blue afterglow materials because of the difficulties in populating and stabilizing excitons at relatively high-lying triplet excited state, although blue/deep blue emissive materials are the essential core elements for achieving solid-state lighting and full-color display. 13,[20][21][22][23] Several groups have worked in developing high quality blue afterglow materials, by modulating the interactions between afterglow emitters and the matrix. For example, Huang's group reported a blue RTP materials through the sensitizing triplet exciton population of tri-mesic acid by cyanuric acid, and afterglow materials with lifetimes up to 1.67 s and QY of 46.1% are developed.…”

Modulating Emission of Organic Emitters from Fluorescence to Red Afterglow through Boric Acid-Assisted Energy Transfer

“…The high-resolution C1s XPS spectrum suggests the presence of multiple carbon-based bonds, such as sp 2 C, C–O, and O–CO, originating from Lev and RhB (Figure d) . Two intensive peaks, located at 532.7 and 531.8 eV, can be obtained in the high-resolution O 1s spectrum of BA@Lev-RhB, which corresponded to B–O and CO, respectively (Figure e). , The high-resolution B 1s spectrum of BA@Lev-RhB was fitted by two peaks, located at 192.7 and 193.6 eV, corresponding to B–O bonds and oxidized boron, respectively (Figure f). , These results confirm successful loading of Lev and RhB into the BA matrix, and the matrix is produced by the dehydration of BA, forming metaboric acid with a small portion of B 2 O 3 .…”

Boosting organic room-temperature phosphorescence performance through joint luminescence sensitization

“…Recently, Adachi et al innovatively exploited the strategy of photoinduced charge transfer to fully utilize the excited state energy in a host-guest doping system, realizing long persistent luminescence that lasted for more than one hour under a nitrogen atmosphere. 1,23 Despite these attractive works, [24][25][26] investigation on the detailed photophysics has rarely been reported, particularly involving multi-step energy transfer processes concerning the host species.…”