Narrow-band Emission Research Articles

A novel fluorescent material K3NbOF6: Mn4+ for light-emitting diode devices

A series of K3Nb1-xOF6:xMn4+ fluorescent materials were prepared by the cation exchange method. Phase structure, morphology, emission, excitation spectrum and LED packaging of fluorescent materials were tested. The fluorescent material particles are micron-sized (5 μm–20 μm) and have a micro-rod morphology. It has two absorption bands, with the blue light region (∼468 nm) being stronger than the ultraviolet region (∼370 nm). Under the excitation of 468 nm, it shows good narrowband emission in the red light region, mainly with anti-stokes v6 (∼627 nm), which is caused by the double barrier of the 2Eg→4A2g transition broken by the coupling effect of electron and phonon. The optimum doping concentration was 9.1 %, and as the concentration increased again, the dipole–dipole interaction between Mn4+ resulted in concentration quenching. When the fluorescent material operates at high temperature (150 ℃), the emission intensity drops to 50.2 % of which at room temperature. At high temperature, the electrons absorb a large amount of heat energy, and the non-radiation transition to 4A2g energy level causes the thermal quenching effect. In addition, the sample also showed good water stability, after 1 h of hydrolysis, the luminescence intensity decreased to 85.6 % of the initial value. The use of LED packaging with fluorescent materials and InGaN-YAG:Ce3+ can effectively reduce the color temperature of LED from 6856 K to 3745 K, and enhance the Color index from 61.5 % to 76.8 %. Which has great potential for development in the fields of plant growth and backlight display technology.

Mn2+–Mn2+ Dimers Induced Robust Light Absorption in Heavy Mn2+ Doped ZnAl2O4 Near‐Infrared Phosphor with an Excellent Photoluminescence Quantum Yield and Thermal Stability

AbstractTransition metal ions, such as Cr3+, Fe3+, and Ni2+, are widely recognized activators for efficient broadband near‐infrared (NIR) phosphors. However, the potential of Mn2+ ions as NIR‐emitting activators is relatively overlooked due to their typically narrowband emission in the visible spectral region and relatively weak absorption. Herein, a heavy Mn2+‐doped Zn1‐xAl2O4: xMn2+ (ZAO: xMn2+) phosphor is presented that exhibits a single NIR emission band peaked at 830 nm with a bandwidth of 135 nm under excitation at 450 nm. Through comprehensive structural and spectral analysis, this NIR band is attributed to the emission originating from Mn2+ ions within the MnO6 octahedra. Importantly, the formation of Mn2+–Mn2+ dimers breaks the spin‐forbidden rule and significantly enhances the transition probability, as supported by the excited state dynamic analysis. Consequently, the optimal ZAO: 0.70Mn2+ sample shows high internal/external photoluminescence quantum yields of 85.8%/36.9%, along with good thermal stability demonstrated by the emission intensity at 423 K retains 60% of that at 298 K. Finally, a prototype NIR pc‐LED device is fabricated by combining ZAO: 0.70Mn2+ phosphor with a 450 nm blue diode chip, generating an NIR output power of 28.84 mW at 100 mA. This study provides novel insights into high‐performance Mn2+‐activated NIR phosphors.

Circularly Polarized Electroluminescence from Intrinsically Axial Chiral Materials Based on Bidibenzo[b,d]furan/bidibenzo[b,d]thiophene

AbstractHerein, by connecting chiral bidibenzo[b,d]furan/bidibenzo[b,d]thiophene and multi‐resonance thermally activated delayed fluorescence (MR‐TADF) units, two pairs of intrinsically axial chiral MR‐TADF materials (R/S‐BDBF‐BNO and R/S‐BDBT‐BNO) realize mirror‐symmetric circularly polarized luminescence (CPL) and narrowband emission. The chiral moieties effectively engage in frontier molecular orbital distributions through the establishment of covalent bonds with boron atoms. The proportions of (1,1′‐bidibenzo[b,d]furan)‐2,2′‐diol in the highest occupied and lowest unoccupied natural transition orbitals (HONTO/LUNTO) are 25.3% and 64.7%, respectively. In addition, BDBT‐BNO processes a dual‐channel transition mode, thus the (1,1′‐bidibenzo[b,d]thiophene)‐2,2′‐diol constitutes 22.8%, 24.3% and 54.0%, 46.9% of the distributions of HONTO, HONTO‐1 and LUNTO, LUNTO+1, respectively. The high proportions endow R/S‐BDBF‐BNO and R/S‐BDBT‐BNO with good CPL properties with dissymmetry factors (|gPL|) of 1.7/1.8 × 10−3. Correspondingly, the circularly polarized organic light‐emitting diodes based on the enantiomers exhibit mirror symmetrical circularly polarized electroluminescence with |gEL| factors of 1.5/1.6 × 10−3. Furthermore, the introduction of sulphur atoms enables BDBT‐BNO to have a high maximum external quantum efficiency of 35.7% in device.

Multiple resonance delayed fluorescence emitter with C3 symmetry for high-performance solution-processed OLEDs

Solution-processed organic materials that exhibit both high emission efficiency and narrowband emission characteristics are rare, and the performance of corresponding solution-processed organic light-emitting diodes (sOLEDs) remains inadequate for practical applications. This study proposes a proof-of-concept design aimed at enhancing both solution processing capability and emission efficiency in multiple-resonance induced thermally activated delayed fluorescence (MR-TADF) materials through the integration of multiple emitting units. A unique emitter named TriBNCz is synthesized and characterized, incorporating three MR-building blocks onto a single phenyl ring, resulting in sky-blue emission with a peak at 490 nm and a small full width at half maximum (FWHM) of 25 nm. Significant improvements in solution processing attributes, including solubility and film-forming properties, are achieved. Moreover, except for the MR effect of the excited states, long-range charge transfer properties of excited states are also obtained. The multiple charge transfer channels contribute to higher rate of reverse intersystem crossing (kRISC). The optimized sOLED device exhibits a maximum external quantum efficiency (EQEmax) of 17.8 %. Furthermore, by employing 5TCzBN as a sensitizer, the sensitized sOLED achieves an EQEmax of 28.8 % and a high-level EQE of 26.1 % at 1000 cd m−2, with an FWHM of 30 nm and Commission Internationale de I’Éclairage (CIE) coordinates of (0.103, 0.497), representing one of the best results among narrowband emission sOLEDs. This research opens a new avenue to develop high-performance solution-processed organic materials and sOLED devices.

Spirobifluorene-appended multi-resonance thermally activated delayed fluorescence emitter for efficient narrowband blue OLEDs with suppressed ACQ effect

Multi-resonance (MR) thermally activated delayed fluorescence (TADF) materials with planar rigidity show great potential as emitters in organic light-emitting diodes (OLEDs) due to their high photoluminescence quantum yields and narrowband emission. However, their strong intermolecular interaction trends usually result in redshifted and broadened emission spectra as well as low device efficiencies due to the aggregation-caused quenching (ACQ) effect. In this paper, a bulky spirobifluorene unit was appended onto an asymmetric carbazole/diphenylamine-embedded MR skeleton to relieve such trends, thus affording a new MR-TADF blue emitter, BNSF-1. Introducing spirobifluorene significantly relieves the intermolecular interaction trends of MR backbones without affecting their original photophysical properties. The corresponding sensitizer-free OLED devices based on BNSF-1 exhibit narrowband sky-blue electroluminescence peaking at 475 nm with a full width at half-maximum of 25 nm, as well as a maximum external quantum efficiency of 25.9 %. More importantly, BNSF-1 exhibited negligible spectral broadening and ACQ trends as the doping ratio increased. Our work provides a feasible method for constructing doping concentration-insensitive MR-TADF emitters.

61‐1: Invited Paper: Polaritonic OLEDs with Assistant Strong‐coupling Layers: A New Approach to Sub‐20nm Emission Linewidth in OLED Displays

With ever more stringent color‐gamut requirements in displays (e.g., BT.2100), there is growing demand for OLEDs with narrowband emission. However, many efficient emitters reported to date show spectrally broad luminescence. Micro‐cavity OLEDs offer narrow linewidth but suffer from changes in spectrum with observation angle. To overcome these limitations, we hybridize microcavity and exciton states in an efficient OLED, thus creating strongly coupled polariton states that inherit the angle insensitivity of excitons and the narrow linewidth of the microcavity. Using assistant strong‐coupling layers located away from the recombination zone yields efficient OLEDs with FWHM <20 nm and angle shift <10 nm @60° tilt.

P‐257: Late‐News Poster: Highly Efficient Geometrically Stretchable Organic Light Emitting Diodes with Angle Independent Narrow‐Band Emission

Herein, we demonstrated the first highly efficient geometrical stretchable top‐emitting organic light emitting diode by incorporating the pre‐stretched optical adhesive (OA) film. The enhancement of device efficiencies with light extraction phenomenon brought by the nanowavy corrugated structures of OA substrate. GSOLED shows stability in stretchable conditions and displays narrowband emission with color purity. The device shows very high current efficiency and EQE of 221 cd A ‐1 and 51 %.

Structurally Tunable Donor-Bridge-Fluorophore Architecture Enables Highly Efficient and Concentration-Independent Narrowband Electroluminescence.

Luminescent materials with narrowband emission have extraordinary significance for developing ultrahigh-definition display. B-N-containing multiple resonance thermally activated delayed fluorescence (MR-TADF) materials are strong contenders. However, their device performances pervasively encounter detrimental aggregation-caused quenching effect that is highly vulnerable to doping concentration, complicating device fabrication. Therefore, constructing highly efficient and concentration-independent MR-TADF emitters is of pragmatic importance for improving device controllability and reproducibility, simplifying manufacturing procedures, and conserving production costs. Here, by systematic arrangement of donor triphenylamine and fluorophore BNCz on distinct bridges, a spatial confinement strategy has been developed with a donor-bridge-fluorophore architecture. Structurally fine modulation and progressive evolution to construct molecular entities with congested steric hindrance effect that can suppress intermolecular interactions without substantially affecting the luminescence tone of fluorophore BNCz, resulting in highly efficient and concentration-independent narrowband emitters; through isomer engineering, two isomers BN-PCz-TPA and TPA-PCz-BN with different crystal stacking patterns are synthesized by altering the connection mode between triphenylamine and BNCz. As a result, BN-PCz-TPA-based device showcases maximum external quantum efficiency (EQE) of 36.3% with narrow full-width at half-maximum of 27 nm at 10 wt% doping concentration. Even at 20 wt% doping concentration, the maximum EQE remains at 32.5% and the emission spectrum is almost unchanged.

Local Light Field Control Enables Efficient Quantum Dot Color Conversion Films for Mini‐LED Backlit Displays

AbstractQuantum dot (QD) color conversion films (QD‐CCFs) are used in ultrahigh definition (UHD) Mini‐LED backlit displays due to their narrow band emission and high color purity. However, their poor light conversion efficiency (LCE) leads to greater film thickness and thus high cost. Herein, this study proposes a local light field control strategy to enhance the LCE of QD‐CCFs using high‐refractive BN nanosheets. The LCEs of the green and red QD‐CCFs can increase from 29.9% and 34.8% to 67.4% and 91.0% after adding BN nanosheets, respectively. Combining the experimental data with the finite‐difference time domain (FDTD) simulations, the enhanced LCEs can be attributed to observably increased blue light absorption and improved light extraction efficiency of the light emitted from QDs. The white Mini‐LEDs, prepared by integrating the optimized QD‐CCFs containing BN nanosheets with blue Mini‐LED chips, show a high luminous efficiency of 70.2 lm W−1, a high external quantum efficiency of 36.2%, and a wide color gamut of 96.3% Rec. 2020 standards. This work provides an interesting idea for designing high‐efficiency QD‐CCFs toward low‐cost UHD Mini‐LED backlit displays.

Single-peak and narrow-band mid-infrared thermal emitters driven by mirror-coupled plasmonic quasi-BIC metasurfaces: publisher’s note

This publisher’s note contains corrections to Optica 11, 305 (2024)OPTIC82334-253610.1364/OPTICA.514203.

Carbon‐Based Photonic Microlabels Based on Fluorescent Nanographene‐Polystyrene Composites

AbstractNanographenes (NGs) are attracting significant interest as atomically‐thin carbon‐based optical nanomaterials exhibiting a wide range of optical properties that are fine‐tuned with ultimate atomic precision though chemical design. However, the use of NGs in photonic applications remains poorly explored. Here a straightforward procedure is demonstrated to load NGs onto the surface of polystyrene microbeads in order to synthesize a functional light emitting microcomposite. The resulting all‐carbon‐based microbeads behave as optical microresonators displaying narrowband emission lines spread across the whole visible spectrum. The unique fluorescent pattern of individual microbeads enables applications in metrology and information encoding. This is shown, as a proof‐of‐concept, by absolute diameter and refractive index estimates of individual polystyrene microbeads with nanometric precision, and the design of an unclonable photonic microtag for anti‐counterfeiting applications. These results pave the way to a new family of carbon‐based microdevices with a wide range of applications in photonics.

Narrowband room temperature phosphorescence of closed-loop molecules through the multiple resonance effect

Luminescent materials with narrowband emission show great potential for diverse applications in optoelectronics. Purely organic phosphors with room-temperature phosphorescence (RTP) have made significant success in rationally manipulating quantum efficiency, lifetimes, and colour gamut in the past years, but there is limited attention on the purity of the RTP colours. Herein we report a series of closed-loop molecules with narrowband phosphorescence by multiple resonance effect, which significantly improves the colour purity of RTP. Phosphors show narrowband phosphorescence with full width at half maxima (FWHM) of 30 nm after doping into a rigid benzophenone matrix under ambient conditions, of which the RTP efficiency reaches 51.8%. At 77 K, the FWHM of phosphorescence is only 11 nm. Meanwhile, the colour of narrowband RTP can be tuned from sky blue to green with the modification of methyl groups. Additionally, the potential applications in X-ray imaging and display are demonstrated. This work not only outlines a design principle for developing narrowband RTP materials but also makes a major step forward extending the potential applications of narrowband luminescent materials in optoelectronics.

Hydrothermal synthesis and photoluminescent properties of (Ca/Sr)2P2O7: Eu2+ pyrophosphate-based blue-emission phosphors

In this work, the luminescent properties of blue-emission (Ca/Sr)2P2O7: Eu2+ phosphors prepared by hydrothermal synthesis method are extensively investigated. The Rietveld refinement verified that Eu2+ was successfully doped into the phosphors. The SEM results showed that the samples of Ca2P2O7 and Sr2P2O7 were composed of tetragonal particles and short nanorods particles, respectively. Under ultraviolet excitation, the blue emission peak of the sample had a small full width half maximum (FWHM), with Ca2P2O7 (λem = 417 nm, FWHM = 24 nm), Sr2P2O7 (λem = 420 nm, FWHM = 28 nm). The quantum efficiencies of Ca2P2O7: Eu2+ and Sr2P2O7: Eu2+ were 70.13 % and 69.26 %, respectively. Under the temperature of 480 K, the luminescence intensity of Ca2P2O7: 0.03Eu2+ and Sr2P2O7: 0.03Eu2+ phosphors decreased to 30.02 % and 82.47 % of the initial intensity. Therefore, (Ca/Sr)2P2O7: Eu2+ phosphors with narrow-band blue emission have potential applications in Light emitting diodes and transparent display.

Narrowband Organic/Inorganic Hybrid Afterglow Materials.

Narrowband afterglow materials display interesting functions in high-quality anti-counterfeiting and multiplexed bioimaging. However, there is still a limited exploration of these afterglow materials, especially for those with a full width at half maxima (FWHM) around 30 nm. Here, we report the fabrication of narrowband organic/inorganic hybrid afterglow materials via energy transfer technology. Coronene (Cor) with a long phosphorescence feature and broad phosphorescence band is selected as the donor for energy transfer, and inorganic quantum dots (QDs) of CdSe/ZnS with a narrowband emission are used as acceptors. Upon doping into the organic matrix, the resultant three-component materials exhibit a narrowband afterglow with an afterglow lifetime of approximately 3.4 s and an FWHM of 31 nm. The afterglow wavelength of the afterglow materials can be controlled by the QDs. This work based on organic/inorganic hybrids provides a facile approach for developing multicolor and narrowband afterglow materials, as well as opens a new way for expanding the features of organic afterglow for multifunctional applications. It is expected to rely on narrowband afterglow emitters to solve the "spectrum congestion" problem of high-density information storage in optical anti-counterfeiting and information encryption.

Highly efficient organic light‐emitting diodes and light‐emitting electrochemical cells employing multiresonant thermally activated delayed fluorescent emitters with bulky donor or acceptor peripheral groups

AbstractMultiresonant thermally activated delayed fluorescence (MR‐TADF) emitters have been the focus of extensive design efforts as they are recognized to show bright, narrowband emission, which makes them very appealing for display applications. However, the planar geometry and relatively large singlet–triplet energy gap lead to, respectively, severe aggregation‐caused quenching (ACQ) and slow reverse intersystem crossing (RISC). Here, a design strategy is proposed to address both issues. Two MR‐TADF emitters triphenylphosphine oxide (TPPO)‐tBu‐DiKTa and triphenylamine (TPA)‐tBu‐DiKTa have been synthesized. Twisted ortho‐substituted groups help increase the intermolecular distance and largely suppress the ACQ. In addition, the contributions from intermolecular charge transfer states in the case of TPA‐tBu‐DiKTa help to accelerate RISC. The organic light‐emitting diodes (OLEDs) with TPPO‐tBu‐DiKTa and TPA‐tBu‐DiKTa exhibit high maximum external quantum efficiencies (EQEmax) of 24.4% and 31.0%, respectively. Notably, the device with 25 wt% TPA‐tBu‐DiKTa showed both high EQEmax of 28.0% and reduced efficiency roll‐off (19.9% EQE at 1000 cd m−2) compared to the device with 5 wt% emitter (31.0% EQEmax and 11.0% EQE at 1000 cd m−2). The new emitters were also introduced into single‐layer light‐emitting electrochemical cells (LECs), equipped with air‐stable electrodes. The LEC containing TPA‐tBu‐DiKTa dispersed at 0.5 wt% in a matrix comprising a mobility‐balanced blend‐host and an ionic liquid electrolyte delivered blue luminance with an EQEmax of 2.6% at 425 cd m−2. The high efficiencies of the OLEDs and LECs with TPA‐tBu‐DiKTa illustrate the potential for improving device performance when the DiKTa core is decorated with twisted bulky donors.

Tunable Narrow-Band Cyan-Emission of Eu2+-doped Nitridomagnesophosphates Ba3-xSrx[Mg2P10N20] : Eu2+ (x=0-3).

Tetrahedron-based nitrides offer a wide range of properties and applications. Highly condensed nitridophosphates are examples of nitrides that exhibit fascinating luminescence properties when doped with Eu2+, making them appealing for industrial applications. Here, we present the first nitridomagnesophosphate solid solution series Ba3-xSrx[Mg2P10N20] : Eu2+ (x=0-3), synthesized by a high-pressure high-temperature approach using the multianvil technique (3 GPa, 1400 °C). Starting from the binary nitrides P3N5 and Mg3N2 and the respective alkaline earth azides, we incorporate Mg into the P/N framework to increase the degree of condensation κ to 0.6, the highest observed value for alkaline earth nitridophosphates. The crystal structure was elucidated by single-crystal X-ray diffraction, powder X-ray diffraction, energy-dispersive X-ray spectroscopy (EDX), and solid-state NMR. DFT calculations were performed on the title compounds and other related highly condensed nitridophosphates to investigate the influence of Mg in the P/N network. Eu2+-doped samples of the solid solution series show a tunable narrow-band emission from cyan to green (492-515 nm), which is attributed to the preferred doping of a single crystallographic site. Experimental confirmation of this assumption was provided by overdoping experiments and STEM-HAADF studies on the series as well on the stoichiometric compound Ba2Eu[Mg2P10N20] with additional atomic resolution energy-dispersive X-ray spectroscopy (EDX) mapping.

Narrow spectra of repeating fast radio bursts: A magnetospheric origin

Fast radio bursts (FRBs) can present a variety of polarization properties and some of them are characterized by narrow spectra. In this work, we study spectral properties from the perspective of intrinsic radiation mechanisms and absorption through the waves propagating in the magnetosphere. The intrinsic radiation mechanisms are considered by invoking quasi-periodic bunch distribution and perturbations on charged bunches moving on curved trajectories. The narrowband emission is likely to reflect some quasi-periodic structure on the bulk of bunches, which may be due to quasi-periodically sparking in a “gap” or quasi-monochromatic Langmuir waves. A sharp spike would appear in the spectrum if the perturbations were to induce a monochromatic oscillation of bunches; however, it is difficult to create a narrow spectrum because the Lorentz factor has large fluctuations, so the spike disappears. Both the bunching mechanism and perturbations scenarios share the same polarization properties, with a uniformly distributed bulk of bunches. We investigated the absorption effects, including Landau damping and curvature self-absorption in the magnetosphere, which are significant at low frequencies. Subluminous O-mode photons cannot escape from the magnetosphere due to the Landau damping, leading to a height-dependent lower frequency cut-off. The spectra can be narrow when the frequency cut-off is close to the characteristic frequency of curvature radiation, however, such conditions cannot always be met. The spectral index is 5/3 at low-frequency bands due to the curvature self-absorption is not as steep as what is seen in observations. The intrinsic radiation mechanisms are more likely to generate the observed narrow spectra of FRBs, rather than the absorption effects.

Enhancing antithermal-quenching properties of terbium-doped phosphors through Nb/Ta substitution: Insights into the role of intervalence charge transfer and excitation-driven modulation

Currently, the unique 5D4 energy level of terbium (Tb3+) can contribute to narrow-band green light emission, which has high application prospects. However, due to its poor thermal stability at high temperatures, how to enhance the antithermal-quenching properties of Tb-doped phosphors has become a research difficulty in the field of solid-state lighting and temperature sensing. In this contribution, the antithermal-quenching green-emitting of terbium was achieved by Nb/Ta substitution to form GdNb1-xTaxO4:Tb3+ phosphors with various components. Photoluminescence analyses reveal an increasing trend in both the optical band gap and the intervalence charge transfer (IVCT) energy level positions with substitution. Variable-temperature spectrums observed that the phosphors under different compositions presented a large discrepancy in thermal quenching performance. It is elucidated that the elevated position of the IVCT energy level (IVCT-EL) predominantly influences thermal quenching, bolstering its role as a compensatory luminescence channel of 5D3→5D4 far more than functioning as a quenching luminescence channel for Tb3+5D3/5D4. Delving into the perspective of IVCT-EL positioning unveils the intrinsic mechanism through which IVCT-EL positions modulate the thermal quenching properties of phosphors with varying compositions due to the substitution of Ta for Nb. This insight facilitates the realization of enhanced thermal quenching resistance in phosphors. Furthermore, the antithermal-quenching property of Tb3+ in single-phase phosphors can be effectively modulated by excitation at different wavelengths. This tuning scheme not only advances the exploration of terbium-doped antithermal-quenching phosphors but also provides a novel strategy and reference for designing green-emitting phosphors in the fields of lighting and sensing.

Tuning of photoluminescence properties: Impact of Pr-doping in SrTiO3 crystallites

Materials having deep blue emission characteristics with a CIEy chromaticity value less than 0.1 are highly desired. Here we incorporated Pr3+ into the Sr2+ site of the Sr1-x PrxTiO3 (x=0.05, 0.075, 0.10, 0.125, 0.15, 0.20) to quench the typical red photoluminescence (PL) emission in Pr-doped compounds and tune it to a blue-emitting system. XRD analysis and structural refinement demonstrate transition from cubic to tetragonal symmetry at Pr concentrations of, x≥0.1. The contribution of oxygen vacancies in emission mechanism was investigated through XPS analysis. High-resolution FE-SEM analysis of morphological features revealed the creation of tiny grains with the appearance of micro pebbles. Under 380 nm UV illumination a narrow-band blue emission peak FWHM of 19.3 nm was obtained at 428 nm for x=0.05. CIE plots were used to examine the quality of emission peaks and samples show CIEy less than 0.1. This blue emission is crucial for lighting and display applications.

Stretchable Metal Halide Perovskite Color Conversion Layers with Block Copolymer Dispersant

AbstractStretchable luminescent nanocomposites with metal halide perovskite (MHP) emitters are in high demand as deformable color‐conversion layers (CCLs) for vivid‐colored form‐factor free displays. However, the immiscibility of the MHP crystals with an elastomeric polymer matrix induces particle aggregation with resultant luminescence quenching, hindering the development of MHP‐based CCLs. Herein, a simple method is proposed to produce highly luminescent MHP nanoparticles (NPs) and stably disperse them in an elastomeric poly(dimethylsiloxane) (PDMS) polymer matrix with block copolymer (BCP) dispersant. The nanocomposites are developed through sequential steps of synthesis of MHP‐NP dispersion solution with BCP and blending with PDMS followed by thermal curing. It is revealed that Lewis basic poly(2‐vinylpyridine)‐block‐poly(dimethylsiloxane) (P2VP‐b‐PDMS) BCP added in the synthesis step promotes crystallization of the MHPs as nanocrystals with an average diameter of 5.9 ± 1.2 nm, whereas MHPs with hundreds of nm are produced without BCP. The resultant MHP‐NPs with P2VP‐b‐PDMS exhibit excellent photophysical properties, such as narrow band emission, high photoluminescence (PL) quantum yield, and long PL lifetime. The MHP‐NPs are stably dispersed in the PDMS matrix by P2VP‐b‐PDMS without particle aggregation, leading to highly deformable and stretchable nanocomposites with stable PL emission upon repetitive stretching, and excellent environmental stability.