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Conventional luminescent information is usually visible under either ambient or UV light, hampering their potential application in smart confidential information protection. In order to address this challenge, herein, light‐triggered luminescence ON‐OFF switchable hybrid hydrogels are successfully constructed through in situ copolymerization of acrylamide, lanthanide complex, and diarylethene photochromic unit. The open‐close behavior of the diarylethene ring in the polymer could be controlled by UV and visible light irradiation, where the close form of the ring features fluorescence resonance energy transfer with the lanthanide complex. The hydrogel‐based blocks with tunable emission colors are then employed to construct 3D information codes, which can be read out under a 254 nm UV lamp. The exposure to 300 nm UV light leads to the luminescence quenching of the hydrogels, thus erasing the encoded information. Under visible light (>450 nm) irradiation, the luminescence is recovered to make the confidential information readable again. Thus, by simply alternating the exposure to UV and visible lights, the luminescence signals could become invisible and visible reversibly, allowing for reversible multiple information encryption and decryption. Light‐triggered luminescence ON‐OFF switchable hybrid hydrogels are synthesized through in situ copolymerization. The hydrogel‐based blocks with tunable emission colors are then employed to construct 3D information codes, allowing for reversible multiple information encryption and decryption.

The random laser was investigated in gold-doped Zinc Oxide nanorods (Au-doped ZnO NRs) under a range of pumping power 0.25 - 4.66 mW. The Au-doped ZnO NRs prepared by chemical bath deposition (CBD) on the ZnO seed layer, were pre-coated on glass substrate using radio frequency magnetron sputtering (Rf-sputtering). The morphological of Au-doped ZnO NRs shows a hexagonal and strong vertically alignment against the substrate. The Energy dispersive spectroscopy (EDX) spectrum and elemental mapping results confirmed that Au atoms (at.%) are doped and spread over the ZnO NRs. More interestingly, the random laser of Au-doped ZnO shows a redshift of ~38 nm. This study showed the ability of using doping as a tuning parameter in the random laser, also provided an emphasis on Au-doped ZnO NRs as suitable options for controllable random laser devices.

Carbon dots (CDs), as a new kind of carbon-based luminescent nanomaterials, have drawn widespread attention in the fields of fluorescence sensing, optoelectronic devices, and biological imaging. This work uses citric acid (CA) and Nile Blue A (NBA) as precursors. By simply changing the solvent in the reaction, their bandgaps were systematically controlled, thereby successfully obtaining bright blue, yellow and red fluorescence emission CDs (B-, Y- and RCDs). The higher quantum yield (QY) of B-, Y- and RCDs are 64%, 57% and 51%, respectively. The selected precursors and different solvents are the key to the formation of three emission CDs. Detailed characterization and density functional theory (DFT) calculations further indicate that the difference in emission color of CDs is due to the size of the sp 2 conjugate domain. In addition, we used multicolor CDs as fluorescent probes to investigate their performance in detection. Among them, BCDs and YCDs can detect Sudan Red I with high selectivity and sensitivity. In the concentration range of 0 to 80 µM, the detection limits are 56 and 41 nM, respectively. Multicolor emitting phosphors and fluorescent films are also obtained by mixing CDs with other matrices. Using Ultraviolet (UV) chip as the excitation source and combining with multicolor fluorescent film and a certain proportion of B-, Y-, and RCDs/epoxy resin composites, bright monochromatic light-emitting diodes (LEDs) and white LED (WLED) with high color rendering index (CRI) were prepared. The above results indicate that the multicolor CDs prepared by us have great application potential in the fields of food safety control and optical devices.

Lead sulfide (PbS) quantum dots (QDs) are important near infrared (NIR) luminescent materials with tunable and strong emission covering a broad NIR region. However, their optical properties are quite sensitive to air, water, and high temperature due to the surface oxidation, thus limiting their applications in optoelectronic devices and biological imaging. Herein, a cation-doping strategy is presented to make a series of high-quality Zn-doped PbS QDs with strong emission covering whole second near-infrared window (NIR-II, 1,000-1,700 nm). First-principle calculations confirmed that Zn dopants formed dopant states and decreased the recombination energy gap of host PbS. Notably, the Zn dopants significantly improved the quantum yield, photoluminescence lifetime and thermal stability of PbS QDs. Moreover, the PEGylated Zn-doped PbS QDs emitting in the NIR-llb window (1,500-1,700 nm) realized the noninvasive imaging of cerebral vascular of mouse with high resolution, being able to distinguish blood capillary. This material not only provides a new tool for deep tissue fluorescence imaging, but is also promising for the development of other NIR related devices.

Metal halide perovskites have unparalleled optoelectronic properties and broad application potential and are expected to become the next epoch-making optoelectronic semiconductors. Although remarkable achievements have been achieved with lead halide perovskites, the toxicity of lead inhibits the development of such materials. Recently, Sb[sup.3+] -activated luminescent metal halide perovskite materials with low toxicity, high efficiency, broadband, large Stokes shift, and emission wavelengths covering the entire visible and near-infrared regions have been considered one of the most likely luminescent materials to replace lead halide perovskites. This review reviews the synthesis, luminescence mechanism, structure, and luminescence properties of the compounds. The basic luminescence properties of Sb[sup.3+] -activated luminescent metal halide perovskites and their applications in WLED, electroluminescence LED, temperature sensing, optical anti-counterfeiting, and X-ray scintillators are introduced. Finally, the development prospects and challenges of Sb[sup.3+] -activated luminescent metal halide perovskites are discussed.

Nowadays, due to uncontrolled synthesis and lack of more direct and systematic evidences, the photoluminescence origin of “zero-dimensional” Cs 4 PbI 6 remains great controversy and the luminescence cannot be controlled. Here we propose a controllable dissolution-recrystallization method to synthesize “emissive” and “non-emissive” Cs 4 PbI 6 nanocrystals (NCs) respectively. Through comparing “emissive” and “non-emissive” Cs 4 PbI 6 NCs, it is clearly proved that the visible emission in “emissive” Cs 4 PbI 6 NCs comes from embedded CsPbI 3 quantum dots (QDs). It is found for CsPbI 3 @Cs 4 PbI 6 nanocomposites, methyl acetate (MeAC) and cyclohexane play an important role in dissolution and recrystallization respectively to obtain Cs 4 PbI 6 matrix and CsPbI 3 cores. Benefiting from this two-step method, the as-synthesized CsPbI 3 @Cs 4 PbI 6 nanocomposites with CsPbI 3 QDs uniformly distributed in Cs 4 PbI 6 matrix are bright with photoluminescence quantum yield (PLQY) up to 71.4% and exhibit improved stability than CsPbI 3 NCs. Moreover, utilizing its formation mechanism, the size of embedded CsPbI 3 QDs can be controlled by reasonable designing the “dissolution” process, so that the luminescence of this CsPbI 3 @Cs 4 PbI 6 nanocomposites can be adjusted in a wide range from green to red (554–630 nm). Our finding not only provides a novel method for synthesizing tunable “emissive” Cs 4 PbI 6 NCs, but also makes clear the photoluminescence origin of “emissive” Cs 4 PbI 6 .

Monomers 4,7-dibromo-2H-benzo[d]1,2,3-triazole (m1) and 4,7-(bis(4-bromophenyl)ethynyl)-2H-benzo[d]1,2,3-triazole (m2) have been synthesized in good yields using different procedures. Monomers m1 and m2 have been employed for building new copolymers of fluorene derivatives by a Suzuki reaction under microwave irradiation using the same conditions. In each case different chain lengths have been achieved, while m1 gives rise to polymers for m2 oligomers have been obtained (with a number of monomer units lower than 7). Special interest has been paid to their photophysical properties due to excited state properties of these D-A units alternates, which have been investigated by density functional theory (DFT) calculations using two methods: (i) An oligomer approach and (ii) by periodic boundary conditions (PBC). It is highly remarkable the tunability of the photophysical properties as a function of the different monomer functionalization derived from 2H-benzo[d]1,2,3-triazole units. In fact, a strong modulation of the absorption and emission properties have been found by functionalizing the nitrogen N-2 of the benzotriazole units or by elongation of the π-conjugated core with the introduction of alkynylphenyl groups. Furthermore, the charge transport properties of these newly synthesized macromolecules have been approached by their implementation in organic field-effect transistors (OFETs) in order to assess their potential as active materials in organic optoelectronics.

Aggregation‐induced emission luminogens (AIEgens) have become a vital class of functional materials for optoelectronic and biomedical applications. Extending AIE behavior from single‐component to two‐component systems opens a new avenue for modulating emission through intermolecular interactions, yet it also introduces substantial complexity in understanding and controlling the aggregation process. In particular, elucidating how multicomponent molecular packing governs macroscopic photophysical behavior remains a central challenge. Herein, we constructed four distinct charge‐transfer (CT) cocrystals through the coassembly of electron‐rich dibenzo‐heterocyclic donors and electron‐deficient 1,2,4,5‐tetracyanobenzene (TCNB) acceptors. The cocrystallization process allows precise manipulation of the dynamic aggregation pathway by tuning the DMSO/H2O ratio. Intriguingly, the morphology evolves from amorphous aggregates to rod‐like and finally to needle‐like microcrystals, showing a nonmonotonic size variation with increasing water content, accompanied by a gradual enhancement of fluorescence intensity. The four CT complexes exhibit wide emission tunability from green to orange‐red, and notably, the AIE‐active DBT/TCNB pair enables a practical demonstration in water‐jet rewritable encryption paper. Overall, this work establishes a simple yet effective paradigm for designing high‐performance solid‐state emitters, while unveiling fundamental principles that govern the controllable molecular assembly in multicomponent luminescent systems. Charge‐transfer coassembly enables precise control over the dynamic aggregation process, resulting in morphology evolution from amorphous aggregates to rod‐like and needle‐like microcrystals, accompanied by a significant fluorescence enhancement. This strategy yields widely tunable solid‐state emission from green to orange‐red, unveiling fundamental principles governing controllable molecular assembly in multicomponent luminescent systems.

Carbon dots (CDs), as the most important type of carbon materials, have been widely used in many fields because of their unique fluorescence characteristics and excellent properties of biocompatibility. In previous studies, the fluorescence of CDs was mainly concentrated in the blue and green, whereas the red fluorescence was relatively less. Herein, we prepared efficient red-emitting CDs from 1,4-diaminonaphthalene using solvothermal methods. We discussed the effects of different solvothermal solvents on CDs. The results show that CDs prepared with octane and acetone as reaction media have the best fluorescence properties. The CDs dispersed in different organic solvents exhibited tunable emission across a wide spectrum from 427 nm to 679 nm. We further demonstrated the application of red light-emitting diode (LED) optoelectronics and fluorescence detection of Fe3+ in aqueous solution.

This paper reports a temperature-tunable conjugated polymer poly[3-(2-ethyl-isocyanato-octadecanyl)-thiophene] (TCP) laser working in superradiant (SR)—or amplified spontaneous emission (ASE)—mode. The absorption spectra indicated the aggregate (mostly dimer) formation upon increasing concentration and/or decreasing temperature. Amplified spontaneous emission (ASE) was observed at suitable concentration, temperature, and pump energy values. The efficiency of the ASE from the TCP polymer was improved by energy transfer from an oligomer 9,9,9′,9′,9″,9″-hexakis(octyl)-2,7′,2′,7″-trifluorene (HOTF). Moreover, the ASE wavelength can be tuned between 550 and 610 nm by changing the temperature of the solution from 60 to 10 °C. To the best of our knowledge, this is the first report of a high-power, temperature-tunable, and conjugated polymer laser.