Photoluminescent Materials Research Articles

Maximized Green Photoluminescence in Tb-Based Metal-Organic Framework via Pressure-Treated Engineering.

Lanthanide metal-organic frameworks are of great interest in the development of photoluminescence (PL) materials owing to their structural tunability and intrinsic features of lanthanide elements. However, there exists some limitations arising from poor matching with metal ions, thereby exhibiting a weak ligand-to-metal energy transfer (LMET) process. Here we demonstrate a pressure-treated strategy for achieving high PL performance in green-emitting Tb(BTC)(H2 O)6 . The PL quantum yield of pressure-treated sample increased from 50.6 % to 90.4 %. We found that the enhanced hydrogen bonds locked the conjugated configuration formed by two planes of carboxyl group and benzene ring, enabling the promoted intersystem crossing to effectively drive LMET. Moreover, the optimized singlet and triplet states also validated the facilitated LMET process. This work opens the opportunity of structure optimization to improve PL performance in MOFs by pressure-treated engineering.

Photoactive CuI-Cross-Linked Polyurethane Materials.

Using multinuclear copper iodide complexes as cross-linking agents in a polyurethane matrix, original photoluminescent stimuli-responsive materials were synthesized. The intrinsic photoluminescence properties of the covalently incorporated copper iodide complexes are thus transferred to the materials while retaining the beneficial characteristics of the polymer host. The transparent materials exhibit room-temperature phosphorescence with emission switching properties by displaying luminescence thermochromism and solvatochromism. The luminescence thermochromism is characterized by a change in the wavelength and intensity of the emission with temperature, and the vapochromic effect presents a contrasted response of extinction or exaltation according to the nature of the solvent of exposure. By combining the luminescence characteristics of photoactive copper iodide complexes with the ease of polymer processing, the application of these luminescent materials as phosphors in LED (light-emitting diode) devices was also demonstrated. The present study shows that the use of copper iodide complexes as cross-linkers in polymeric materials is a relevant strategy to design materials with enhanced functionalities in addition to their low cost and sustainable characteristics.

Mycosynthesis of highly fluorescent selenium nanoparticles from Fusarium oxysporum, their antifungal activity against black fungus Aspergillus niger, and in-vivo biodistribution studies.

In the past few years, photo-luminescent inorganic materials have been studied extensively as fluorescent sensors, and diagnostic and bioimaging tools. The assessment of photoluminescence (PL) properties of selenium nanoparticles (Se NPs), especially mycosynthesized Se NPs, is still in its infancy. Herein, we have biosynthesized highly dispersed fluorescent Se NPs (42 nm) using endophytic fungus Fusarium oxysporum, and fully characterized them using sophisticated instruments like TEM, XRD, UV–Vis spectrophotometer, FTIR, and PL spectrometer. To determine the therapeutic efficacy and side effect profiles, these crystalline Se NPs were radiolabeled with technetium-99m (99mTc) and their biodistribution and renal clearance times were investigated in the normal Wister rat. The results showed that these Se NPs may be useful for targeting the lungs and liver dysfunction as significant accumulation of these NPs was observed in the liver (approx. 19.47 ± 4%) and lungs (at 6 ± 1%) after 10 min of post-injection. Quick circulation and the presence of Se NPs in kidney (3.8 ± 2%) also suggested the easy excretion of these NPs from the body through urinary tract. Furthermore, the antioxidant activity of Se NPs (IC50, 159.5 μg/mL) has been investigated using DPPH free radical scavenging assay with scavenging efficacy of 80.4% where ascorbic acid (IC50, 5.6 μg/mL) was used as a positive control. Additionally, the microscopic study of the inhibition zone encircled around Se NPs confirmed their strong antifungal and antisporulant activity against the black fungus Aspergillus niger.

Luminescent fac-[ReX(CO)3(phenyl-pyta)] (X = Cl, Br, I) complexes: influence of the halide ligand on the electronic properties in solution and in the solid state.

Tricarbonylrhenium(I) complexes that incorporate a chloride ligand are promising photoluminescent materials, but those incorporating a bromide or iodide ligand have received very little attention regarding their solid-state properties. In this work, three rhenium(I) complexes differing only by the nature of their halide ligand (X = Cl, Br, and I) were compared. They are based on a fac-[ReX(CO)3(N^N)] framework where the N^N bidentate ligand is a 3-(2-pyridyl)-1,2,4-triazole unit functionalized by an appended phenyl group. DFT calculations showed that the character of the lowest energy transitions progressively changes from Re → N^N ligand (MLCT) to X → N^N ligand (XLCT) when increasing the size of the halogen atom. Regarding the electrochemical behavior, the chloride and bromide complexes 1-Cl and 1-Br were similar, while the iodide complex 1-I exhibited a strikingly different electrochemical signature in oxidation. From a spectroscopic viewpoint, all three complexes emitted weak red-orange phosphorescence in dichloromethane solution. However, in the solid state, marked differences appeared. Not only was 1-Cl a good emitter of yellow light, but it had strong solid-state luminescence enhancement (SLE) properties. In comparison, 1-Br and 1-I were less emissiveand they showed better mechanoresponsive luminescence (MRL) properties, probably related to a loose molecular arrangement in the crystal packing and to the opening of vibrational non-radiative deactivation pathways. This study highlights for the first time how the nature of the halide ligand in this type of complex allows fine tuning of the solid-state optical properties, for potential applications either in bio-imaging or in the field of MRL-active materials.

Total Luminescence Spectroscopy for Quantification of Temperature Effects on Photophysical Properties of Photoluminescent Materials.

Quantification of the temperature effects on the optical properties of photoluminescent (PL) materials is important for a fundamental understanding of both materials optical processes and rational PL materials design and applications. However, existing techniques for studying the temperature effects are limited in their information content. Reported herein is a temperature-dependent total photoluminescence (TPL) spectroscopy technique for probing the temperature dependence of materials optical properties. When used in combination with UV-vis measurements, this TPL method enables experimental quantification of temperature effects on fluorophore fluorescence intensity and quantum yield at any combination of excitation and detection wavelengths, including the fluorophore Stokes-shifted and anti-Stokes-shifted fluorescence. All model polyaromatic hydrocarbon (PAH) and xanthene fluorophores exhibited a strong excitation- and emission-wavelength dependence in their temperature effects. However, the heavy-atom effects used for explaining the strong temperature dependence of brominated anthracenes are not operative with xanthene fluorophores that have heavy atom substitutions. The insights from TPL measurements are important not only for enhancing the fundamental understandings of the materials photophysical properties but also for rational measurement design for applications where the temperature sensitivity of the fluorophore fluorescence is critical. An example application is demonstrated for developing a sensitive and robust ratiometric fluorescence thermometric method for in situ real-time monitoring of sample temperatures inside a fluorescence cuvette placed in a temperature-controlled sample holder.

Polarity‐triggered anti‐Kasha system for high‐contrast cell imaging and classification

AbstractKasha's rule, which states that all exciton emissions occur from the lowest excited state and are independent of excitation energy, makes high‐energy excitons difficult to use and severely hinders the widespread applications of organic photoluminescent materials in the real world. For decades, scientists have tried to break this rule to unleash the power of high‐energy excitons, but only minimal progress has been achieved, with no rational guiding principles provided, and few applications developed. So far, breaking Kasha's rule has remained a purely academic concept. In this paper, we introduce a design principle for a purely organic anti‐Kasha system and synthesise a series of compounds based on the design rule. As predicted, these compounds all display evident S2 emissions in dilute solutions. In addition, we introduce a highly accurate (over 90%) convolutional neural network as an assistant for the classification of cells using anti‐Kasha luminogens, thereby providing a new application direction for anti‐Kasha systems.

Layer-by-Layer Deposition of 2D CdSe/CdS Nanoplatelets and Polymers for Photoluminescent Composite Materials.

Two-dimensional (2D) semiconductor nanoplatelets (NPLs) are strongly photoluminescent materials with interesting properties for optoelectronics. Especially their narrow photoluminescence paired with a high quantum yield is promising for light emission applications with high color purity. However, retaining these features in solid-state thin films together with an efficient encapsulation of the NPLs is a challenge, especially when trying to achieve high-quality films with a defined optical density and low surface roughness. Here, we show photoluminescent polymer-encapsulated inorganic-organic nanocomposite coatings of 2D CdSe/CdS NPLs in poly(diallyldimethylammonium chloride) (PDDA) and poly(ethylenimine) (PEI), which are prepared by sequential layer-by-layer (LbL) deposition. The electrostatic interaction between the positively charged polyelectrolytes and aqueous phase-transferred NPLs with negatively charged surface ligands is used as a driving force to achieve self-assembled nanocomposite coatings with a well-controlled layer thickness and surface roughness. Increasing the repulsive forces between the NPLs by increasing the pH value of the dispersion leads to the formation of nanocomposites with all NPLs arranging flat on the substrate, while the surface roughness of the 165 nm (50 bilayers) thick coating decreases to Ra = 14 nm. The photoluminescence properties of the nanocomposites are determined by the atomic layer thickness of the NPLs and the 11-mercaptoundecanoic acid ligand used for their phase transfer. Both the full width at half-maximum (20.5 nm) and the position (548 nm) of the nanocomposite photoluminescence are retained in comparison to the colloidal CdSe/CdS NPLs in aqueous dispersion, while the measured photoluminescence quantum yield of 5% is competitive to state-of-the-art nanomaterial coatings. Our approach yields stable polymer-encapsulated CdSe/CdS NPLs in smooth coatings with controllable film thickness, rendering the LbL deposition technique a powerful tool for the fabrication of solid-state photoluminescent nanocomposites.

Controllable self-assembly of thiophene-based π-conjugated molecule and further construction of pillar[5]arene-based host-guest white-light emission system

Photoluminescence materials have been widely applied in biological imaging and sensing, anti-counterfeiting, light-emitting diodes, logic gates et al. The fabrication of luminescent materials with adjustable emission color by self-assembly of π-conjugated molecules has attracted particular attention. In this study, we designed and synthesized a thiophene-based α-cyanostyrene-derivative (TPPA), then investigate its self-assembly morphology and fluorescence emission under different organic solvents, different proportions of H2O/THF (DMSO) mixture and different pH conditions by UV, FL and SEM images. It was found that TPPA formed nanoparticles by self-assembly in organic solvent (THF or DMSO), accompanied by strong fluorescence emission. However, with the increase of water ratio, the fluorescence intensity decreased accompany with red shift, and the self-assembly morphology changed from nanoparticles to fibers. More interestingly, when pillar[5]arene (P5) was added to form host-guest complex with TPPA, white light emission could be successfully constructed when the ratio of TPPA to P5 was 1:20 and THF to water was 19:1.

Photoluminescent and photocatalytic behaviour of zinc oxide nanostructures synthesized through the room temperature ultrasonication method.

In the present article we report the synthesis of zinc oxide (ZnO) nanostructures at room temperature using an ultrasonication technique to study their photoluminescent and photocatalytic behaviour. Synthesized nanomaterial showed a strong near band edge ultraviolet (UV) light emission and red emission, thereby finding its use in photoluminescent materials. We developed a UV/ZnO/O2 /H2 O2 system for the photodegradation of organic pollutants in an aqueous system. We used synthesized nanostructures to photodegrade phenol red (PR) dye to check their photocatalytic activity. The ZnO nanostructures photodegraded more than 90% of the PR dye under UV light irradiation in which photonic energy is converted to chemical energy (photocatalytic energy conversion), thereby exploitable for water purification applications. Synthesized ZnO nanostructures were characterized using powder X-ray diffraction, Fourier transform infrared spectroscopy, UV-visible light spectroscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy to investigate their structural, optical, morphological, and compositional properties, respectively.

Competitive Dual-Emission-Induced Thermochromic Luminescence in Organic-Metal Halides.

Lead-free Halides, especially Mn-based ones, are preferred as hotspots in the exploration of photoluminescent materials. However, there are few reports on sensitive reversible thermochromism and switchable dual emission originating from self-trapped exciton emission in pure Mn-Based materials. Here, we report a new Mn-based hybrid material [TMPA]2MnI4 (TMPA = trimethylphenylammonium), which shows two emission peaks at 545 and 660 nm benefitting from the d-d orbital transition of Mn2+ and the generation of self-trapped excitons, respectively. Due to the different sensitivity to temperature, the stages of thermal activation and thermal quenching of the two emission types are also inconsistent, showing a certain competition relationship and dominating the emission colors in different temperature ranges, resulting in adjustable green-orange-green thermochromic luminescence from 100 to 403 K (both high and low temperatures correspond to green, and orange is displayed at near room temperature). Therefore, thermochromic luminescence can be easily achieved by controlling the temperature under the guidance of excited states. This work provides new insights into the synthesis and application of thermochromic materials. Therefore, it is certain that regulating temperature while being guided by excited states will achieve thermochromic luminescence. This research offers fresh perspectives on the development and potential of thermochromic materials.

Photoluminescence Study of Silver Nanoparticles Decorated on Multiwall Carbon Nanotubes (MWCNTs) by Spectroflourometer

Multiwall carbon nanotubes (MWCNTs) have recently attracted much attention due to their appealing properties in several domains. Multiwall carbon nanotubes (MWCNTs) were functionalized in this research study and then decorated with silver nanoparticles. Fourier transform Infrared Spectroscopy (FTIR) was used to check the successful attachment of hydroxyl (OH) and carboxyl (C=O) groups with MWCNTs. XRD analysis was used to check the crystallite size of silver nanoparticles and the decoration of silver nanoparticles on MWCNTs. Pure Carbon nanotubes (CNTs) show luminescence in an infrared region having approximately 1.3 eV absorption band. At room temperature, our hybrid material's photoluminescence (PL) spectra indicate only one peak in the UV region and many high-intensity peaks in the visible region. These PL results show the change in the band structure of Ag/MWCNTs composite compared to pure silver nanoparticles and carbon nanotubes. Therefore, it unlocks the possibilities to use this hybrid material for bio-sensing and bio-imaging devices, chemical sensing devices, optoelectronics devices, drug delivery devices, cancer cell detection, and environment detection devices.

Effect of Structural Variation on Spectral, NLO Properties, and Biological Activity of Pyrrole Hydrazones.

This paper describes spectral, non-linear optical (NLO), and biological activity variation of pyrrole hydrazones as a result of structural variation. In order to study structure–property variation, pyrrole hydrazones (3A, 3B, and 3C) were synthesized in both solid and solution phases. The grinding solvent-free method becomes rapid, easy, convenient, useful, sustainable, and eco-friendly green synthesis as compared to the classical solution phase reactions. The structure of pyrrole hydrazones has been elucidated by microanalysis and quantum chemical calculations. The intense emission at λem 521 nm (3A and 3B) and 617 nm (3C) in the visible (green and orange) region with Stokes shifts at 195, 160, and 282 nm reveals that the studied compounds work as good photoluminescent materials. All compounds show strong n−π* and charge transfer (π–π*) transitions in the UV–vis region with high extinction coefficients. In the studied systems (3A, 3B, and 3C), the orbital overlap between σ(NH–O) → σ*(NH–O) is found due to intra-molecular charge transfer. The first hyperpolarizabilities were found to be 48.83 × 10–30 esu for 3B and 63.89 × 10–30 esu for 3C, showing variation with structure. Their high values indicate more suitability for NLO application. Incorporation and/or change in position of electron-withdrawing groups increase the β0 values of 3B and 3C compared to 3A. The β value also increases monotonically as the polarity of the solvents increases. The red shift in N–H and C=O stretching Fourier-transform infrared bonds is due to the formation of dimers. The synthesized 3A, 3B, and 3C show good antimicrobial activity and are predicted to be potential antibacterial and antifungal drugs. The 3B has more molar refractivity (122.16 esu) than 3A and 3C and correlates well with the calculated binding affinity and experimental antimicrobial data.

A thermoplastic polyurethane/rare earth composite film with adjustable fluorescence colors and optimal low‐temperature flexibility

AbstractIn this study, a unique series of luminous polymeric rare earth (RE) composite films was produced by loading RE ions into thermoplastic polyurethane (TPU) using solution blending. Compared to RE ions, luminous polymeric RE composites had greater luminescence intensity, indicating that the introduction of polymer polyurethane as the polymer matrix was advantageous for the luminescence intensity and efficiency of RE ions, with the polymer matrix's absorbed energy being transferred to the RE ions. Furthermore, the findings of the optical transmittance, UV–visible absorption and fluorescence emission spectra suggest that TPU‐RE composite films possess exceptional fluorescence luminescence properties and optical transparency. Surprisingly, the fluorescence colors of TPU‐RE fluorescent films could be adjusted between red and green by varying the ratios of Eu3+ and Tb3+ in the films and can be any mixture of red and green hues. In addition, the temperature at 5% weight loss (T5%) for the TPU‐RE composite film composition reached 250 °C. In addition, pure TPU and all TPU‐RE hybrid films demonstrated a glass transition temperature (Tg) of about −30 °C. Simultaneously, the tensile strength of the TPU‐T0E10 film reached its maximum (43.6 MPa). Consequently, the TPU‐RE composite films will be utilized as photoluminescent functional materials. © 2022 Society of Industrial Chemistry.

Modulating Resonance Energy Transfer with Supramolecular Control in a Layered Hybrid Perovskite and Chromium Photosensitizer Assembly.

Recently, the low-dimensional organic-inorganic halide perovskites (OIHP) have been exploited heavily for their favorable exciton dynamics, broad-band emission, remarkable stability, and tunable band-edge excited-state energy compared to their 3D counterparts for potential optoelectronic applications. Low-dimensional perovskites are generally good candidates for utilization as room-temperature photoluminescence (PL) materials. Further, doping divalent transition metals like Mn2+ into OIHP is expected to introduce a 4T1-6A1-based low-energy luminescence emission around 600 nm; an optical property that is favorable for biomedical optoelectronics. Doping Mn2+ in the perovskite lattice is also expected to induce the generation of cytotoxic singlet oxygen species (1O2), a ROS that is being exploited for various therapeutic applications. To integrate these optical and therapeutic properties of a 2D (PEA)2PbBr4 (Pb PeV; PEA = phenylethylammonium cation) perovskite alloyed with Mn2+ ions (Mn:PbPeV) and the option for a photoinduced energy transfer process involving a Cr(III)-based 1O2 generating photosensitizer (CrPS), we designed a unique purpose-built nanoassembly (Mn:PbPeV@PCD) using the encapsulation properties of a water-soluble polymer derived from β-cyclodextrin (PCD). Here the PCD is observed to modulate the classical internal energy transfer of Pb2+ exciton to alloyed Mn2+ orange emission, resulting in the emergence of a new blue emission. The addition of CrPS into the Mn:PbPeV@PCD to generate the CrPS@Mn:PbPeV@PCD assembly results in restoring perovskite luminescence followed by the external energy transfer to CrPS. We have elucidated the mechanism of these cascade energy transfer processes between multiple components using steady-state and time-resolved luminescence techniques. Efficient ROS generation and its potential to induce an oxidation reaction of a biomolecule are realized using guanine as the target molecule. Further photoinduced cleavage studies with biomolecules confirmed the efficacy of the nanoassembly in inducing the cleavage of guanine-rich DNA. The study opens up a new direction in the field of perovskite for biomedical applications.

Towards field implementation of photoluminescence in the built environment for passive cooling and lighting energy efficiency

Photoluminescent materials are widely considered crucial elements in sustainable lighting, and they are also gaining credit in passive cooling applications in buildings. In this study, we investigate different photoluminescent pigments, connecting their emission behavior to the specific afterglow color and evaluating their potential use as passive cooling and lighting energy-saving solutions. In particular, we analyze the spectral behavior of the selected pigments to obtain for the first time corrected luminescence spectral responses. The same materials are then characterized through photometric methods, considering realistic environmental boundary conditions to better evaluate their potential as light sources in a real urban environment. Results demonstrate the influence of spectral properties and irradiation power on the registered radiance of the pigments. Furthermore, the presence of simultaneously excited multiple emitters produces non-negligible differences between the emission spectra from the monochromatic and the full range excitation procedure. At the same time, an almost perfect agreement can be found in the case of single emitters. Finally, the data are discussed to present the complementarity between passive cooling andlighting actions.

Development of Precisely Controlled Structures Containing Main Group Elements for Preparing Superatoms

Abstract This review summarizes our recent studies of main group elements of boron, aluminum, gallium and bismuth units with dendrimer templates. Stepwise assembly of bismuth salts realized tunable photoluminescent materials according to the introduced amounts. Solid-state emission and switching of optical properties were demonstrated by using a shell-effect of the dendrimer. BH3 species placed in the dendrimer acted as a reductant in the nanosized space to form size-controlled metal particles. Atomicity control for AlCl3 or GaCl3 enabled a solution-phase synthesis of superatoms, which have been expected to be new building blocks for materials.

Photoluminescence and Fluorescence Quenching of Graphene Oxide: A Review.

In recent decades, photoluminescence (PL) material with excellent optical properties has been a hot topic. Graphene oxide (GO) is an excellent candidate for PL material because of its unique optical properties, compared to pure graphene. The existence of an internal band gap in GO can enrich its optical properties significantly. Therefore, GO has been widely applied in many fields such as material science, biomedicine, anti-counterfeiting, and so on. Over the past decade, GO and quantum dots (GOQDs) have attracted the attention of many researchers as luminescence materials, but their luminescence mechanism is still ambiguous, although some theoretical results have been achieved. In addition, GO and GOQDs have fluorescence quenching properties, which can be used in medical imaging and biosensors. In this review, we outline the recent work on the photoluminescence phenomena and quenching process of GO and GOQDs. First, the PL mechanisms of GO are discussed in depth. Second, the fluorescence quenching mechanism and regulation of GO are introduced. Following that, the applications of PL and fluorescence quenching of GO–including biomedicine, electronic devices, material imaging–are addressed. Finally, future development of PL and fluorescence quenching of GO is proposed, and the challenges exploring the optical properties of GO are summarized.

Li+ doping induced zero-thermal quenching in Cs3Zn6–x–yB9O21:xEu3+,yLi+ (0 ≤ x ≤ 0.10, 0.06 ≤ y ≤ 0.16)

Thermal stability is a crucial index to assess application value of high-power LEDs, which is related to lattice defects. Herein, an effective structure-engineering strategy is proposed to achieve excellent properties. Under the 394 nm excitation, Cs3Zn5.94B9O21:0.06Eu3+ possesses two characteristic emissions peaked at 591 and 612 nm with limited thermal stability. By introducing Li+ ions into the lattice, the sample exhibits high color purity and excellent zero-thermal quenching because the defect contents of the phosphor can be effectively modulated via charge-compensation effect. Then, under the stimulus of high temperature, the corresponding trap levels with a suitable depth (E = 1.27 eV) will release electrons to recombine with the luminescent centers, compensating for the energy loss. The study provides a meaningful guide for optimizing and designing novel functional photoluminescent materials.

A novel ratiometric fluorescence sensor based on lanthanide-functionalized MOF for Hg2+ detection

Post-synthesis modification is an effective strategy for the preparation of rare earth organic framework materials and the derivation of high-performance functional materials. Here, we report the preparation of a dual emission Ln-MOF material (Eu-Ca-MOF) using Ca-MOF as the parent framework and introducing Eu3+ ions into its channels through post-synthesis modification. Eu-Ca-MOF has good photoluminescence properties and can be used as a ratiometric fluorescence sensor (I381/I590) to detect Hg2+ ions in water sensitively. The characteristic of Eu-Ca-MOF obtained is that when the material is dispersed in an aqueous solution containing Hg2+ ions, the characteristic emission of the ligand at 381 nm is enhanced, while the characteristic emission of Eu3+ at 590 nm is quenched. The peak-to-height ratio of the two emissions can be used to achieve highly sensitive detection of Hg2+ ions even in the presence of other potentially competing analytes. In addition, Hg2+ induces Eu-Ca-MOF to produce a significant ratiometric luminescence response, which changes its luminescence color from red to blue, which is beneficial to visual analysis of naked eyes. At the same time, Eu-Ca-MOF has a wider detection range (0.02–200 μM), and a lower limit detection (2.6 nM) for Hg2+ ions. The lanthanide compounds prepared by post-synthetic modification provide an effective synthesis strategy for photoluminescent materials.

Boric Acid‐Activated Room‐Temperature Phosphorescence and Thermally Activated Delayed Fluorescence for Efficient Solid‐State Photoluminescence Materials

AbstractThe construction of highly luminescent solid‐state materials with long‐lived afterglow through a straightforward method is promising but still a challenging task. Herein, a heat‐treatment strategy is proposed to embed levofloxacin (Lev) in the matrix of boric acid (BA) to produce a complex with a photoluminescence quantum yield of 63.8% and an emission lifetime of 0.74 s (afterglow: >5 s). Detailed investigations suggest that the unique photophysical properties of the complex are attributed to the confinement effect of BA matrix to Lev, which reduces the probability of nonradiative relaxation and activates the radiative decays to result in the promoted emission efficiency. In addition, thermally activated delayed fluorescence is also activated due to the alteration of the π transition of Lev by the formation of boron–carbon bonds. The emission color and lifetime are also modulated through controlling the synthetic conditions, which endow their applications both in light‐emitting diodes and information encryption. Thus, the present results are significant for the construction of solid‐state luminescent materials, including fluorescence and room‐temperature phosphorescence, and also provide a solid and universal theory to clarify their detailed emission profiles.