Regardless of rapid development of organic room-temperature phosphorescence (RTP) originating from phosphors in crystals, highly efficient and persistent RTP from common fluorophores is very rare. Herein, 1,8-naphthalimide (NI), a common organic fluorophore, is doped into organic cations of 2D layered organic/inorganic hybrid perovskites (OIHPs) to yield thin films and powders with yellow RTP of NI in air. The triplet excitons of NI are mainly derived from Wannier excitons of inorganic perovskite through energy transfer (ET) for films, and from singlet excitons of NI through intersystem crossing (ISC) for powder. Consequently, the quantum yield (ΦP), lifetime (τ) and color of RTP can be tuned by changing the fluorophore and halide in the perovskites, as well as their solid morphology. A white emission, comprising the blue one from the perovskite and yellow RTP (ΦP = 25.6%, τ = 6.3 ms) from NI, is obtained in Br-based OIHPs in powder. Cl-based OIHPs exhibit fluorescence/phosphorescence dual emission in thin films, and yellow afterglow phosphorescence in powders (ΦP = 56.1%, τ = 35 ms). The unique performance of the OIHPs with RTP can make them widely applicable in the field of information technology as security ink, and white and afterglow LEDs as single luminescent materials.
Ultralong and colorful clusterization-triggered phosphorescence (CTP) has been realized by changing polymerization conditions of polyacrylamides (PAMs). These materials have huge potential in the application of sensing, anti-counterfeiting and LEDs.
6 February 2019 in Journal of Materials Chemistry C
A simple organic molecule, 2-(9H-carbazol-9-yl)ethanol (CZEO), displays both mechanoluminescence (ML) and photo-induced room-temperature phosphorescence (RTP). The D–A type dimer formed in the crystals was found to play a crucial role in the light-stimulated luminescent response, responsible for the turn-on RTP and turn-off ML switching of CZEO.
24 January 2017 in Journal of Materials Chemistry C
Diarylmaleic anhydride derivatives containing benzene (BPMA), thiophene (BTMA) and indole (BIMA) exhibit diverse and distinct fluorescence: aggregation-caused quenching (ACQ) of red emission of BIMA, blue aggregation-induced emission (AIE) of BPMA, and green dual-state emission (DSE) of BTMA in both solution and the solid state. Theoretical calculation and crystal structure analysis indicate that intramolecular and intermolecular interactions are responsible for their different emission behavior. A series of DSE-active molecules with full-color emission could be developed for the first time, through modification of the structures of BPMA and BIMA. Interestingly, BTMA and BPMA display multi-stimuli-responsive luminescence with a high-contrast (Δλem > 100 nm) and an unusual photochromic phenomenon in dichloromethane, which were utilized to construct rewritable data storage and mimic molecular logic operation (4-to-2 encoder and 1 : 2 demultiplexer), respectively.
A novel Λ-shaped donor–π–acceptor–π–donor molecule BCPMM with AIEE, CIEE and polymorphism-dependent fluorescence properties was utilized to construct five simple logic gates and more than ten kinds of sequential combinational logic systems.
A kind of metal-free organic ammonium halides characterized by a unique 2D layered structure show colorful ultralong phosphorescence. Phosphorescent quantum yield (up to 19%) and lifetime (up to 1.7 s) can be tuned by doping with different phosphors.