National Television System Committee Research Articles

ZnO induced self-crystallization of CsPb(Br/I)3 nanocrystal glasses with improved stability for backlight display application

• With further the integration of green-emitting CsPbBr3@glasses powder, a flexible film with white light-emitting were obtained by sandwiching and gluing mixed glasses powders between two layers of hydrophobic and transparent PET films. • A high-resolution backlight image is acquired by putting PET composite film into the backlight device. • The content of lead can hardly dissolve from ZnO induced self-crystallized CsPb(Br/I)3@glass, indicating its excellent environmental friendliness. • The maximum PLQY of the obtaining CsPb(Br/I)3@glass composite is of 30% with the content of ZnO was 13 mol%. • The FWHM (34–44 nm) can be well modified by tailoring the content of ZnO. • ZnO can not only be used as a flux to reduce the sintering temperature of glass, but also as a network modifier to make the glass structure more stable. • wLEDs are constructed and applied in backlit display, achieving a color gamut covering up 126% of NTSC and 93.4% of Rec. 2020. • The outstanding stability towards water, cyclic thermal and 455 nm LED irradiation benefit from the protection of the robust glass matrix. In the current situation of energy shortages, saving energy and reducing consumption are undoubtedly valid methods to relieve the pressure on resources. CsPb X 3 ( X = Cl, Br, and I) perovskites as star inorganic materials have drawn growing attention owing to their unique properties, making them suitable for applications such as light-emitting diodes (LEDs), solar cells, photodetectors, or lasers. This work presents zinc oxide (ZnO) induced self-crystallized CsPb(Br/I) 3 perovskite with a 26% photoluminescence quantum yield (PLQY) prepared by the traditional melt-quenching method. Furthermore, the full width at half maximum (FWHM) (34–44 nm) can be regulated by the ZnO content. In addition, as a downconverter, CsPb(Br/I) 3 perovskite nanocrystals (NCs) realize a bright red backlight that covers ≈ 94% Rec. 2020 standards in the CIE 1931 color space and 126% of National Television System Committee (NTSC). This finding undoubtedly confirms an effective path for fabricating perovskite materials in a green, low-cost, and time-saving way, enriching the knowledge of glass crystallization mechanisms and promoting their applications in wide color gamut backlights.

Manganese activated narrowband red-emitting Cs2KInF6:Mn4+ phosphor with high colour purity for backlight display

A series of Mn4+ doped cubic phase Cs2KInF6 red phosphors (abbreviated here as CKIFM) were obtained through a typical co-precipitation route. The optical and structural properties of this material were researched in more detail using X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL) and photoluminescence excitation (PLE), diffuse reflectance spectroscopy (DRS), temperature-dependent PL and lifetimes. Interestingly, the as-prepared CKIFM phosphors have a strong and broad absorption band in the blue area with a peak at 468 nm, and bright narrow-band red fluorescence with high colour purity. Furthermore, the optimum quenching concentration, crystal field parameters (CFPs), internal quantum efficiency (IQE), and the corresponding concentration quenching mechanism are discussed and analyzed in detail. Finally, the WLED backlight using the obtained CKIFM red-emitting phosphor and β-SiAlON:Eu2+ (β-Sialon:Eu2+) green-emitting phosphor demonstrates a wide color gamut (∼101.7% National Television System Committee standard (NTSC)), revealing the title phosphor is an attractive red component for backlight displays.

Investigation of highly luminescent inorganic perovskite nanocrystals synthesized using optimized ultrasonication method

All-inorganic halide perovskite nanocrystals are next-generation materials with excellent optical and semiconductor properties suitable for display applications. In this study, we introduce an optimized ultrasonication method for the high-capacity synthesis of highly luminescent inorganic perovskite nanocrystals. After the synthesis of CsPbBr3 with superior optical performance by ultrasonication method, halide anion exchange was performed to tune the stable emission wavelength over the entire visible range. In particular, the maximum photoluminescence wavelengths of the red and green perovskite nanocrystals were appropriate for light-emitting diode applications, and their full-width-at-half-maximum were very narrow, showing outstanding color purity. The materials also had excellent thermal and photo-stability, which is a necessary requirement for perovskite nanocrystal/organic light-emitting diode hybrid device applications. We formulated uniformly stable perovskite nanocrystal inks and optimized their physical and rheological properties for successful inkjet-printing. Finally, we fabricated a hybrid device with a color conversion layer based on the red and green perovskite nanocrystals synthesized using the optimized ultrasonication and halide-ion-exchange methods. The color reproduction range of the fabricated devices was 27.3 % wider than that of the National Television System Committee values, indicating very vivid colors.

Tuning Intramolecular Stacking of Rigid Heteroaromatic Compounds for High‐Efficiency Deep‐Blue Through‐Space Charge‐Transfer Emission

A series of ultrapure-blue thermally activated delayed fluorescence (TADF) emitters featuring through-space charge transfer (TSCT) were constructed via close stacking between donor and acceptor in rigid heteroaromatic compounds. The obviously accelerated radiative transition of singlet excitons, the diminished vibrionic relaxation of ground and excited states, consequently the reduced Stokes shift and the narrow emissioncan be found. The corresponding organic light-emitting diodes (OLEDs) based on AC-BO realize the best performance among all deep-blue TSCT-TADF emitters with an external quantum efficiency (EQE max ) of 19.3%. Meanwhile, the OLEDs based on QAC-BO display an EQE max of 15.8%, which achieve the first high-efficiency ultrapure-blue TSCT-TADF material with an excellent Commission Internationale de L'Eclairage coordinate (CIE) of (0.145, 0.076) which perfectly match the ultrapure-blue requirements of CIE (0.14, 0.08) defined by the National Television System Committee.

Tuning Intramolecular Stacking of Rigid Heteroaromatic Compounds for High‐Efficiency Deep‐Blue Through‐Space Charge‐Transfer Emission

AbstractA series of ultrapure‐blue thermally activated delayed fluorescence (TADF) emitters featuring through‐space charge transfer (TSCT) have been constructed by close stacking between the donor and acceptor moieties in rigid heteroaromatic compounds. The obviously accelerated radiative transition of singlet excitons, the diminished vibrionic relaxation of ground and excited states, and the consequent reduced Stokes shift and the narrow emission are evident. The corresponding organic light‐emitting diodes (OLEDs) based on AC‐BO realize the best performance among all deep‐blue TSCT‐TADF emitters, with an external quantum efficiency (EQEmax) of 19.3 %. Furthermore, the OLEDs based on QAC‐BO display an EQEmaxof 15.8 %, and achieve the first high‐efficiency ultrapure‐blue TSCT‐TADF material with an excellent Commission Internationale de L'Eclairage coordinate (CIE) of (0.145, 0.076) which perfectly matches the ultrapure‐blue CIE requirements (0.14, 0.08) defined by the National Television System Committee.

CsPbBr3 nanocrystals encapsulated in silica molecular sieve as a stable green light emitting material for backlight display

CsPbBr3 nanocrystals (NCs) with highly efficient narrow-band green emission are promising candidates in display applications. However, the poor stability of CsPbBr3 NCs is always a challenge for future development. Herein, CsPbBr3 NCs encapsulated into MCM-41 molecular sieve (MS) composite were designed and prepared via an optimized ultrasonic and stirring treatments, and the as-obtained green-emitters exhibited tunable green emission at the range of 508–523 nm via different concentrations adjustment in perovskite and heat-treatment conversion. In addition, a narrow full-width at half-maximum (FWHM) of 23 nm can be achieved when the PL emission was 523 nm. More excitingly, the optimal photoluminescence quantum yield (PLQY) was as high as 45%. Subsequently, the CsPbBr3@MS composites exhibit outstanding stabilities, showing no loss even after immersing in water for 10 days or irradiated by the 455 nm white light emitting device (WLED) for 2 days. Finally, based on such excellent properties, the WLED composed of green light-emitting CsPbBr3@MS composite, commercial blue chip and red K2SiF6:Mn4+ (KSF) phosphors realized an ultrawide color gamut, covering 125% National Television System Committee (NTSC). Moreover, the best coordinates of green light are (0.1622,0.7513), the composite film prepared with silica gel achieves white color coordinates of (0.3133, 0.2834) at the same time, of which were all meet the commercial standard coordinates. This work highlights the encapsulation process and feasible solid-state reaction methodology to fabricate CsPbBr3 NCs confined in a microporous molecular sieve with high luminescent stability and performance, significantly expanding its great potential in optoelectronic fields.

Experimental and theoretical studies of red emission enhancing mechanism in Al-doped CaMoO4:Eu phosphor

In this work, a complete picture of the relationship between the structural and optical properties of Al-doped CaMoO4:Eu phosphor was investigated empirically and theoretically. A series of Al-doped CaMoO4:Eu phosphors were synthesized by solid-state reaction. X-ray diffraction analysis and Rietveld refinement confirmed the formation of a single-phase tetragonal CaMoO4. Under the excitation wavelength of 395 nm, the phosphors exhibited typical red emission bands of Eu3+ as a function of Al3+ doping contents and reached a maximum value at 0.1 mol % Al3+. In addition, the CaMoO4:0.05Eu, 0.1Al phosphor showed chromaticity coordinates (0.6406, 0.3370), which is close to the pure red color as standardized by the National Television System Committee. Significantly, the red emission intensity of Al-doped CaMoO4: 0.05Eu phosphor was 5-times higher than that of the undoped one. This enhancement was explained by Judd-Ofelt (JO) analysis, from which intensity parameters (Ωλ, λ = 2, 4) and radiative properties including branching ratios (βr), transition probability (A), radiative lifetime (τcal), and stimulated emission cross-section (σe) of the phosphor were derived. Judd-Ofelt analysis confirmed that Al3+ promotes the covalent character in the Eu–O bond and the asymmetry in the CaMoO4 crystalline structure. The CaMoO4: 0.05Eu, 0.1Al phosphor generates strong red emission and possesses high values of branching ratio (81.80%), emission cross-section (102.3×10−22 cm2) and quantum efficiency (48.44%) and is potential for low-cost WLED applications.

Utilizing a strait-range green phosphor γ-AlON:Mn,Mg for the task of achieving a super-broad hue gamut display

<span><span>The screen backlighting produced by green β-sialon:Eu, as well as red K<sub>2</sub>SiF<sub>6</sub>:Mn phosphors, have an extremely expansive hue gamut that encompasses the majority of the </span></span>national television system committee <span>(NTSC) triangle. For our research, a substitute phosphor in green would be probed in terms of improving the screen hue range even further. The phosphor γ-AlON:Mn,Mg appears to be green in color with a smaller radiation band of colors than sharp β-silaon:Eu. By replacing γ-AlON:Mn,Mg with β-sialon:Eu, the screen hue range in the blue-green area is significantly expanded. In both the CIE 1931 and CIE 1976 hue spaces, the hue range of screens with γ-AlON:Mn,Mg, and K<sub>2</sub>SiF<sub>6</sub>:Mn entirely surpasses the NTSC benchmark. Furthermore, the stability of LEDs emit white light using γ-AlON:Mn,Mg appears to be similar to LEDs that utilize β-sialon:Eu.</span>

Molecular doped, color-tunable, high-mobility, emissive, organic semiconductors for light-emitting transistors.

Developing high-mobility emissive organic semiconductors with tunable colors is crucial for organic light-emitting transistors (OLETs), a pivotal component of integrated optoelectronic devices, but remains a great challenge. Here, we demonstrate a series of color-tunable, high-mobility, emissive, organic semiconductors via molecular doping with a high-mobility organic semiconductor, 2,6-diphenylanthracene, as the host. The well-matched molecular structures and sizes with efficient energy transfer between the host and guest enable the intrinsically high charge transport with tunable colors. High mobility with the highest value >2 cm2 V−1 s−1 and strong emission with photoluminescence quantum yield >15.8% are obtained for these molecular-doped organic semiconductors. Last, a large color gamut for constructed OLETs is up to 59% National Television System Committee standard, meanwhile with an extremely high current density approaching 326.4 kA cm−2, showing great potential for full-color smart display, organic electrically pumped lasers and other related logic circuitries.

Single‐Layer Sheets of Alkylammonium Lead Iodide Perovskites with Tunable and Stable Green Emission for White Light‐Emitting Devices

AbstractRecently, metal halide perovskites have attracted considerable interest as highly emissive phosphors for use in white light‐emitting diodes (WLEDs). In perovskites, the migration of halide anions between green‐emitting bromide (e.g., CsPbBr3) and red‐emitting iodide (e.g., CsPbI3) materials is one obstacle to application. Here perovskite WLEDs that do not suffer from the anion exchange problem are reported: this is done by developing green‐emitting single‐layer sheets of (RNH3)2PbI4 (R = C18H35–, C12H25–, and C8H17–) and uniting these with red‐emitting CsPbI3 perovskite quantum dots (QDs). It relies on self‐assembly from ligand‐capped CsPbI3 nanocrystals to form single‐layer sheets of (C18H35NH3)2PbI4: via judicious selection of alkylamines and alkyl acids, (RNH3)2PbI4 single‐layer sheets that exhibit bright and stable green emission with well‐defined single‐layer thickness are produced. Emission from 505, 512 to 536 nm is tuned and a narrow (<20 nm) linewidth is retained. Perovskite LEDs that produce white light with chromaticity coordinates (0.32, 0.33) and color gamut that reaches 117% National Television System Committee (NTSC) in the International Commission on Illumination (CIE) 1931 color space are demonstrated.

New deep blue fluorophores based on benzo[d]thiazole group as acceptor core: Theoretical, synthesis, photophysical and electroluminescent investigation

Deep-blue organic emitters have attracted considerable attention from both industrial as well as academic research in organic light-emitting diodes (OLEDs). In this context, three novel deep blue fluorophores based on benzothiazole 2-(4'-(1,4,5-triphenyl-1H-imidazole-2-yl)-[1,1′-biphenyl]-4-yl)benzo [d]thiazole (PHBISN), 2-(4'-(1-(4-(tert-butyl)phenyl)-4,5-diphenyl-1H-imidazole-2-yl)-[1,1′-biphenyl]-4-yl)benzo [d]thiazole (PTBISN) and 2-(4'-(4,5-diphenyl-1-(3-(trifluoromethyl)phenyl)-1H-imidazole-2-yl)-[1,1′-biphenyl]-4-yl)benzo [d]thiazole (m-CFBISN) were designed and synthesized. The fluorophores were structurally characterized and a detailed computational study reveals the compounds with wide energy gap (>3eV). The thermal properties, photophysical and electronic properties were systematically investigated. Photoluminescence and electroluminescence study shows fluorophores with deep blue emission. Novel synthesized fluorophores exhibit good performance for deep-blue solution-processed OLEDs. The doped device based on PTBISN shows the highest performance with deep blue electroluminescent and maximum EQE 1.5% with CIE color coordinates of (0.15, 0.08), which is near to the blue standard (0.14, 0.08) of the National Television System Committee (NTSC).

High-performance red phosphorescent light-emitting diodes built on bipolar host materials obtained from dibenzo[F,H]quinoxaline and dibenzothiophene

DTBDQ, a bipolar host material with an acceptor unit dibenzo[F,H]quinoxaline and a donor unit dibenzothiophene connected by two interstitial benzenes, was employed. DTBDQ exhibits deep LUMO and HOMO energy levels, along with a triplet energy of 2.75 eV, owing to rational molecular design. Red phosphorescent organic light-emitting diodes (PhOLEDs) devices with DTBDQ here as the host and Ir(piq)2acac as the guest layer have an external quantum efficiency(EQE) of 19.79% with a limited roll-off and an EQE of 18.08% at 1000 cd/m2, with CIE coordinates of (0.68,0.32), which is quite comparable to the National Television Systems Committee (NTSC) CIE coordinates of (0.67,0.33). The device performance is significantly better than that of devices using hole-type host CBP, electron-type host TPBI, and electron and hole-type hosts together, indicating that the performance of bipolar host materials transferring both electrons and holes is superior to that of simply two hosts as a double light-emitting layer separately, which is beneficial to carrier transport balancing and avoiding carrier buildup. DTBDQ demonstrates that it is an excellent bipolar host candidate.

Highly effective surface defect passivation of perovskite quantum dots for excellent optoelectronic properties

Metal halide perovskite quantum dots (QDs) are next-generation materials with excellent optical and electrical properties suitable for display applications. However, their significantly large surface-area-to-volume ratio makes them highly susceptible to surface defects. In this study, we developed an effective passivation strategy that uses various imide derivatives (namely, caffeine, 4-amino-N-methylphthalimide, and 6-amino-1,3-dimethyluracil) to synthesize high-performance perovskite QDs. Caffeine or 6-amino-1,3-dimethyluracil significantly improved the optical properties and thermal stability by passivation of under-coordinated Pb2+ ions of the perovskite QDs. Moreover, these aided the removal of black dots that act as trap states, thereby yielding pure crystals. In contrast, 4-amino-N-methylphthalimide passivation led to deterioration of the optical properties and poor crystal purity because of its intrinsic impurities (black dots). Molecular calculations confirmed that the atomic charge of the carbonyl oxygen of the imide derivatives was proportional to the efficacy of passivation. The caffeine-passivated perovskite QDs were used to fabricate red, green, and blue light-emitting diodes. The current and external quantum efficiencies of these devices were significantly improved compared to those of the devices with pristine perovskite QDs. The color coordinate values of the fabricated devices showed an ultra-wide color gamut of 130% National Television System Committee.

Highly Efficient and Thermally Stable Ba0.75Al11O17.25: Eu2+, Mn2+ Phosphor with Dual Narrowband Blue and Green Emissions: A Promising Candidate for Wide Gamut Displays

The discovery of Eu2+‐activated narrowband green phosphor is pivotal for wide gamut liquid crystal displays (LCDs) but facing a great challenge due to the broadband emitting nature of Eu2+ ions. Alternatively, Mn2+ ions can generate extremely narrow green emission band but suffering from their weak absorption. Herein, Eu2+ ions with strong absorption are used to sensitize Mn2+ ions in the Ba0.75Al11O17.25 host. The Mn2+ ions exhibit a green emission band peaked at 515 nm with an extremely narrow bandwidth of 27 nm. More importantly, the Eu2+ ions show strong absorption at 340–380 nm and a blue emission band peaked at 450 nm with a relatively narrow bandwidth of 51 nm. Thus, the Ba0.75Al11O17.25: Eu2+, Mn2+ phosphor can be used as a dual narrowband blue and green emitting phosphor with commercial ultraviolet diode chips excitation. Moreover, this phosphor exhibits impressive overall performance that fulfills the key standards of commercial phosphors, including high emission efficiency, excellent photoluminescence thermal stability, and outstanding chemical stability. The packaged light‐emitting diode (LED) using 365 nm chips, Ba0.75Al11O17.25: Eu2+, Mn2+ and K2TiF6:Mn4+ phosphor generates a ultrawide color gamut of 121% National Television Systems Committee (NTSC) in Commission Internationale de l'Eclairage 1931 (CIE 1931).

Highly Efficient and Stable Eu3+-Doped CsPbBr3/Cs4PbBr6 Perovskites for White Light-Emitting Diodes

All-inorganic halide perovskite nanomaterials have a high application potential in the field of display and lighting because of unique photoelectric properties. However, these materials suffer from problems related to poor water and thermal stabilities. In this study, green Eu3+-doped CsPbBr3/Cs4PbBr6 perovskite composites that were synthesized by a saturated recrystallization method at room temperature showed an enhanced photoluminescence quantum yield of 87% and superior water and thermal stabilities to that of undoped perovskites. Finally, green Eu3+-doped CsPbBr3/Cs4PbBr6 perovskite composites were fabricated into white light-emitting diodes (WLEDs) with a wide color gamut (124% of the National Television System Committee standard) and a high efficiency of 43.06 lm/W.

Green emanating BiOCl:Tb3+ phosphors for strategic development of dermatoglyphics and anti-counterfeiting applications

• Green emitting BiOCl:xTb 3+ (x = 1–9 mol%) nanophosphors are prepared by propellant solution combustion route. • A new fluorescence based platform has been setup for in-situ visualization of latent fingerprints and lip prints by powder dusting method. • Well defined fluorescence fingerprint images on variety of surfaces by revealing type 1–3 ridge characteristics. • Developed latent fingerprints shows superior contrast, sensitivity, efficiency, selectivity and negligible background hindrance. • Fabricated unclonable invisible security ink and make it highly suitable for brush mode. In this work, we reported green emitting Tb 3+ ions (1–9 mol%) doped BiOCl nanophophors (NPs) synthesized by solution combustion route using Mimosa pudica ( M. p. ) plant extract as a bio-fuel. Powder X-ray diffraction (PXRD) patterns exhibit tetragonal structure of matlockite-type P4/nmm space group. Scanning electron microscopy (SEM) reveals that the prepared NPs were shown flake-like morphology. The energy bandgap of BiOCl:Tb 3+ (1–9 mol%) NPs were estimated and found to be in the range ∼3.50–3.53 eV. The photoluminescence (PL) spectra show characteristic emission peaks at ∼489, 545, 591 and 622 nm, which were corresponding to 5 D 4 → 7 F 6, 5 D 4 → 7 F 5 , 5 D 4 → 7 F 4 and 5 D 4 → 7 F 3 transitions of Tb 3+ ions, respectively. The maximum PL intensity was found to be for 5 mol% doped NPs and later diminishes. The diminished PL intensity was mainly ascribed to concentration quenching. The estimated CIE (Commission International de I’Eclairage) co-ordinates were close to the green emission standard values set by the National Television System Committee. The optimized NPs was used for development and visualization of latent fingerprints (LFPs) and lip prints. The developed fingerprints and lips prints revealed level I-III ridge details with high sensitivity, selectivity and without any background hindrance. The developed anti-counterfeiting labels were encrypted only under UV light illumination, but were completely invisible under normal light. These results clearly demonstrated that the optimized NPs can help to narrow the search gap in criminal investigations and forensic purposes.

Full-Color Quantum Dot Light-Emitting Diodes Based on Microcavities

Full-color display is a primary challenge for the commercialization of quantum dots (QDs). In this study, we utilize the spectral narrowing phenomenon of microcavities to fabricate the red, green and blue quantum dot light-emitting diodes (QLEDs) with a single QD layer. This work theoretically analyses the role of microcavities in adjusting the emitting color of QLEDs. By enhanced microcavity and properly chosen spacer thickness, the spectral selectivity shifts, realizing the full-color-tunability of QLEDs. The tunable experimental spectra of microcavity QLEDs are observed, in excellent agreement with our theoretical design. Benefiting from the spectral narrowing of microcavity and the narrow spectra of QDs, a high color purity with full width at half maximum (FWHM) of 18 to 25 nm is realized, leading to a color gamut ratio of 104.8% compared to National Television System Committee (NTSC) standard. The light extraction is also enhanced by constructive interference and the Purcell effect in the microcavity. Moreover, in the fabrication of red, green, and blue pixels, patterning the transparent cathode has better feasibility and lower damage relative to patterning the light-emitting layer.

High efficiency fluorescent perovskite quantum dots encapsulated in superhydrophobic silica aerogel for wide color gamut backlight displays

• A super-hydrophobic Silica Aerogels film for backlight display was prepared. • A wide gamut of 128% of color gamut of NTSC standard was achieved. • Excellent environmental stability was achieved through a composite strategy. Recently, all-inorganic cesium lead halide (CsPbX 3 ) perovskite quantum dots (PQDs) have been widely used in the photoelectric field. However, a major limitation of solution-processed PQDs for applications is inherent instability. Herein, we adopt strategy of passivation, CsPbX 3 (X = Cl, Br, I) PQDs are encapsulated into super-hydrophobic silica aerogels (SiO 2 AGs) to form a protective layer for resisting destruction by external forces. Importantly, the photoluminescence quantum yield (PLQY) of CsPbBr 3 @AGs composites achieves 71%, CsPbCl 2 Br 1 @AGs, CsPbBr 3 @AGs and CsPbBr 1 I 2 @AGs composites with narrow emissions can replace traditional phosphors as color converters. In addition, a high-performance liquid crystal display (LCD) with a wide color gamut (128% of National Television System Committee color space) is demonstrated using the prepared CsPbX 3 @AGs@PS composite film and blue light emitting diode (LED) chip as backlight. The combination of improved stability and wide color gamut of the perovskite material provides a viable approach for LCD backlight.

In Situ Growth of Ultrapure Green‐Emitting FAPbBr3‐PVDF Films via a Synergetic Dual‐Additive Strategy for Wide Color Gamut Backlit Display

AbstractElaborate engineering of emitting wavelength of green down‐converter in the spectral range of ≈525–535 nm with narrow full‐width at half‐maximum (fwhm < 25 nm) is an essential prerequisite for faithfully reproducing colors in the quantum dot (QD)‐based backlit display. Herein, different from the previous complex synthesis for green films, FAPbBr3 perovskite QDs films are fabricated by a dual‐additive assisted in situ growth strategy. Both C6H5CH2CH2NH3+ and 1,4,7,10,13,16‐hexaoxacyclooctadecane additives are introduced to synergistically tune green emitting (≈525–535 nm) with the narrowest fwhm down to 21 nm and the highest photoluminescence quantum yield (PLQY) up to 99%. Improved nanocomposite film with excellent long‐term stability is used to construct a prototype liquid crystal display (LCD) with a wide color gamut (118% National Television System Committee and 88% Recommendation BT 2020), a high saturation, and a remarkable color rendition. The performance is superior to that of the commercial white‐LED‐based LCD, showing a great potential of the present green film for high‐definition display application in the future.

MAPbBr3 nanocrystals from aqueous solution for poly(methyl methacrylate)-MAPbBr3 nanocrystal films with compression-resistant photoluminescence

In this work, we develop an environmental-friendly approach to produce organic-inorganic hybrid MAPbBr3 (MA = CH3NH3) perovskite nanocrystals (PeNCs) and PMMA-MAPbBr3 NC films with excellent compression-resistant PL characteristics. Deionized water is used as the solvent to synthesize MAPbBr3 powder instead of conventionally-used hazardous organic solvents. The MAPbBr3 PeNCs derived from the MAPbBr3 powder exhibit a high photoluminescence quantum yield (PLQY) of 93.86%. Poly(methyl methacrylate) (PMMA)-MAPbBr3 NC films made from the MAPbBr3 PeNCs retain ∼97% and ∼91% of initial PL intensity after 720 h aging in ambient environment at 50 °C and 70 °C, respectively. The PMMA-MAPbBr3 NC films also exhibit compression-resistant photoluminescent characteristics in contrast to the PMMA-CsPbBr3 NC films under a compressive stress of 1.6 MPa. The PMMA-MAPbBr3 NC film integrated with a red emissive film and a blue light emitting source achieves an LCD backlight of ∼114% color gamut of National Television System Committee (NTSC) 1953 standard.