Herein, new types of zero‐dimensional (0D) perovskites (PA6InCl9 and PA4InCl7) with blue room‐temperature phosphorescence (RTP) were obtained from InCl3 and aniline hydrochloride. These are highly sensitive to external light and force stimuli. The RTP quantum yield of PA6InCl9 can be enhanced from 25.2 % to 42.8 % upon illumination. Under mechanical force, PA4InCl7 exhibits a phase transform to PA6InCl9, thus boosting ultralong RTP with a lifetime up to 1.2 s. Furthermore, white and orange pure RTP with a quantum yield close to 100 % can be realized when Sb3+ was introduced into PA6InCl9. The white pure phosphorescence with a color‐rendering index (CRI) close to 90 consists of blue RTP of PA6InCl9 and orange RTP of Sb3+. Thus, this work not only overcomes long‐standing problems of low quantum yield and short lifetime of blue RTP, but also obtains high‐efficiency white RTP. It provides a feasible method to realize near‐unity quantum efficiency and has great application potential in the fields of optical devices and smart 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.
In conventional n–i–p perovskite solar cells (PVSCs), electron donor (D)–acceptor (A) polymers have been found to be potential substitutes for doped spiro‐based small molecule hole‐transporting materials (HTMs) due to their excellent performance in hole mobility, film formability, and stability. Herein, a benzo[1,2‐b:4,5‐b′]dithiophene (BDT)‐benzodithiophene‐4,8‐dione (BDD) copolymer PBDB‐Cz is developed by employing carbazole as the conjugated side chain of BDT. PBDB‐O and PBDB‐T with alkoxy and thiophene as the side chain of BDT, respectively, are also synthesized and studied for comparison. The synergistic effect of the carbazole side chain and the BDT‐BDD backbone to promote hole transport properties is found in PBDB‐Cz. The carbazole side chain enhances both coplanarity and interaction of polymer chains, while simultaneously deepening energy levels and improving the hole mobility of the polymeric HTM. Consequently, PBDB‐Cz outperforms two counterparts, exhibiting a promising power conversion efficiency (PCE) of 22.06%. Notably, the PBDB‐Cz also improves the device stability, and the devices can retain more than 90% of their initial PCEs after being stored at ambient conditions for 100 days. To the best of the authors’ knowledge, this is the first report to incorporate carbazole into D–A polymeric HTM by side chain engineering.
Organic afterglow materials (OAMs) with a lifetime longer
than 0.1 s have recently received much attention for their fascinating
properties meeting the critical requirements of applications in newly
emerged technologies. However, the development of OAMs lags behind
for their low luminescence efficiency. Usually, enhancing the phosphorescence
efficiency of organic materials causes a short lifetime. Here, we
report two kinds of OAMs, two-dimensional (2D) layered organic–inorganic
hybrid zinc bromides (PEZB-NTA and PEZB-BPA), obtained in an environmentally
friendly ethanol solvent by a low-temperature solution method. They
display highly efficient and persistent luminescence in air in both
crystals and thin films with phosphorescence quantum yields up to
42% in crystals and 27% in films. For OAMs, the two quantum yields
are the highest values ever reported for crystals and films. Due to
the excellent crystalline and film-forming ability, PEZB-NTA and PEZB-BPA
in ethanol can be used as inks to construct patterns on various rigid
and flexible substrates, including paper, iron, plastic, marble, tin
foil, and cloth. Consequently, the novel OAMs show great application
prospects in the fields of anti-counterfeiting and information storage
because of their economic synthesis, solution processing, and easy
operation.
2D organic–inorganic hybrid perovskites (OIHPs) show obvious advantages in the field of optoelectronics due to their high luminescent stability and good solution processability. However, the thermal quenching and self‐absorption of excitons caused by the strong interaction between the inorganic metal ions lead to a low luminescence efficiency of 2D perovskites. Herein, a 2D Cd‐based OIHP phenylammonium cadmium chloride (PACC) with a weak red phosphorescence (ΦP < 6%) at 620 nm and a blue afterglow is reported. Interestingly, the Mn‐doped PACC exhibits very strong red emission with nearly 200% quantum yield and 15 ms lifetime, thus resulting in a red afterglow. The experimental data prove that the doping of Mn2+ not only induces the multiexciton generation (MEG) process of the perovskite, avoiding the energy loss of inorganic excitons, but also promotes the Dexter energy transfer from organic triplet excitons to inorganic excitons, thus realizing the superefficient red‐light emission of Cd2+. This work suggests that guest metal ions can induce host metal ions to realize MEG in 2D bulk OIHPs, which provides a new idea for the development of optoelectronic materials and devices with ultrahigh energy utilization.
The dispersion of noble metal nanoparticles (NPs) over the surface of two-dimensional (2D) transition metal dichalcogenide (TMDs) creates an efficient electrocatalytic framework which combines the superior catalytic capability of noble...
Herein, two maleimide derivatives substituted by Br (DBM) and I (DIM) with a two-dimensional (2D) layered structure are found to have highly efficient red roomtemperature phosphorescence (RTP) at 660 nm in solid state, which is independent of their morphology (crystal, powder, and film). The red RTP of DBM and DIM is closely related to the synergism of n π -ct-π* transitions and the 2D halogen-bonded network. Interestingly, the red RTP can be excited by visible light of 500 nm, which should be ascribed to the forbidden absorption from the ground state to the triplet state activated in the layered halogen-bonded framework. Due to the rich intermolecular interactions in the rigid layered structure, the red RTP of DBM is very stable under water or external force stimulation. Notably, Hg(II) and Cd(II) ions in a pure aqueous solution result in an opposite change in the RTP intensity of the DBM film. The detection limit of Hg(II) ion is as low as 2.5 × 10 −5 nM, lesser than all reported values. The above results not only provide a new idea for the design of simple and efficient red RTP materials but also make it possible to develop solid-state phosphorescent probes for toxic heavy metal ions in environmental sewage with high sensitivity and selectivity.
Organic-inorganic hybrid perovskites (OIHPs) with white emission have recently attracted much attention because they can be used as single-component luminescent materials in UV chip driven white-light-emitting diodes (WLEDs). However, low...
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