Materials Today Chemistry
·
2024
·
IF 6.7
Pinyi He,Jianliang Bai,Fu Qin,Xinyu Wang,Xu Yu,Yongkang Yao,Lili Ren
Deep-blue emission (＜450 nm) is significant in high-density information storage, solid-state lighting, and vivid displays. However, the carbon dots (CDs) obtained from p-phenylenediamine (pPD) have only red fluorescence, which greatly limits the application and development of pPD-based CDs. As we all know, a catalyst is a substance that can change the rate and pathway of a chemical reaction. Herein, we designed to add a catalyst to realize the conversion of pPD-based CDs from red to deep-blue fluorescence. The emission peak of obtained deep-blue CDs was 440 nm, and the full-width at half-maximum (FWHM) was only 58 nm, with a high color purity. In addition, through in-depth analysis of microstructure and photoluminescence (PL) properties, it is found that the decrease of the sp 2 -conjugated domain and the graphite N content and the increase in pyridinic N content were the main reasons for the blue shift of the spectra. Based on this, the formation process and mechanism of red and deep-blue CDs were further elucidated. This work not only efficiently realized the design of the deep-blue CDs but also provided a new idea for the luminescence regulation of CDs without changing the raw materials and reaction conditions.
研究领域:
材料科学
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光学
✓ 已验证
DOI
高影响因子
Light-Science & Applications
·
2025
·Vol. 14
·期 1
·1-10
·
IF 23.4
Yu Mubing,Qin Tingxiao,Gao Gang,Zu Kelei,Zhang Dongming,Chen Nan,Wang Dengke,Hua Yong,Zhang Hong,Zhao Yong-Biao,Zhu Jiaqi
Deep-blue perovskite light-emitting diodes (PeLEDs) based on reduced-dimensional perovskites (RDPs) still face a few challenges including severe trap-assisted nonradiative recombination, sluggish exciton transfer, and undesirable bathochromic shift of the electroluminescence spectra, impeding the realization of high-performance PeLEDs. Herein, an in situ chlorination (isCl) post-treatment strategy was employed to regulate phase reconstruction and renovate multiple defects of RDPs, leading to superior carrier cooling of 0.88 ps, extraordinary exciton binding energy of 122.53 meV, and higher photoluminescence quantum yield of 60.9% for RDP films with deep-blue emission at 450 nm. The phase regulation is accomplished via fluorine-derived hydrogen bonds that suppress the formation of small- n phases. Multiple defects, including halide vacancies (shallow-state defects) and lead-chloride antisite defects (deep-state defects), are renovated via C=O coordination and hydroxy-group-derived hydrogen bonds. Consequently, deep-blue PeLEDs with a record maximum external quantum efficiency of 6.17% and stable electroluminescence at 454 nm were demonstrated, representing the best-performing deep-blue PeLEDs.
研究领域:
材料科学
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光学工程
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半导体物理
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产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2022
·Vol. 10
·期 13
·5284-5291
·
IF 8.067
Wenyan Huang,Yeqi Zhu,Lei Zhong,Chao Jin,Yinong Zheng,Yinggan Zhang,Siqi Lan,Shiwen Gong,Jiangnan Zhao,Meng Huang,Rongqian Yao
Designing deep-blue emitting materials with integrated high quantum yields and easy film-forming ability is challenging. As a typical organosilicon polymer, polycarbosilane (PCS) with a –Si–C– repeated backbone has received much attention owing to its high stability, versatile optical properties, easy solubility and film-forming ability. Herein, an ingenious strategy toward enhanced photoluminescence characteristics was successfully introduced to obtain a series of σ–π conjugated PCS containing dimethylsilane-aryl (phenylene, diphenylene, fluorenyl) backbones via the Grignard reaction. Such synergistic effects of –Si–C– and aryl endow the products with high quantum yields and easy large-size forming ability in a simple and economical manner. Particularly, polyfluorenecarbosilane (PFCS) exhibits excellent deep-blue light emission (λmax = 414 nm) with a high quantum yield (up to 89.75%), which is the highest value ever reported for organosilicon polymers to the best of our knowledge. It is demonstrated that the findings offer new opportunities for the development of flexible, foldable and stretchable organic devices.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2024
·
IF 18.5
Xinyao Yan,Rui Cao,Ruxi Zhang,Haotian Gao,Yin Xiao
This study presents the development of mixed-ligand quasi-2D perovskites ((2-PEA) x ( R/S -2-BA) 2 MA 1 Cs 1 Pb 3 Br 10+ x , x = 0.8, 1.6, 2.4) for circularly polarized light-emitting diodes (CP-LEDs). By utilizing the strong confinement effect of 2-phenylethylammonium (2-PEA) and the chirality of R / S -2-butylammonium ( R/S -2-BA), room-temperature circularly polarized luminescence (CPL) across the green to deep blue spectrum is achieved. The green CPL attributes to the transfer of spin-polarized excitons while the blue CPL originates from direct excitation of luminescent phases with intrinsic chirality. Finally, green and blue CP-LEDs under ambient are realized. Notably, standard and deep blue CP-EL is achieved based on 0.8PEA/( R/S -2-BA)- and 1.2PEA/( R/S -2-BA)-films with impressive electroluminescent asymmetry factors (0.122 and 0.175), highlighting the potential of chiral perovskites in CP-LEDs and opening avenues for the development of room-temperature full-color CP-EL display.
研究领域:
材料科学
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光学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
Nano Energy
·
2022
·
IF 19.069
Fei Gao,Xiaonan Zhu,Qiushi Feng,Weiheng Zhong,Weizhen Liu,Haiyang Xu,Yichun Liu
Lead-free metal halide perovskites are promising materials for future optoelectronic application , which have recently attracted great attention for their environmental-friendliness and excellent light emission properties. However, the development of deep-blue emission lead-free halide perovskite nanocrystal is still far behind in performance in comparison with its red/green counterparts. Herein, the lead-free Cs 3 Cu 2 I 5 nanocrystals are prepared via a modified hot-injection strategy. By adding InI 3 as precursor, the synthesized Cs 3 Cu 2 I 5 single-phase nanocrystals show a bright deep-blue emission peaked at ~440 nm, with a record high photoluminescence quantum yield (PL QY) up to 96.6% at an optimized InI 3 content of 0.15 mmol. The InI 3 additive contributes to the high PL QY through both iodide vacancy reparation of I - ions and size-controlled growth of In 3+ ions. First principle calculations reveal that the broadband blue emission originates from self-trapped excitons in Cs 3 Cu 2 I 5 , which are formed due to the excited-state lattice expansion and Cu-I bond lengthening of [Cu 2 I 5 ] 3- cluster under light excitation . The good stabilities of these Cs 3 Cu 2 I 5 nanocrystals against heat, water, UV irradiation and environmental storage are also investigated experimentally and theoretically in detail. For application demonstration, light-emitting devices are manufactured by using these Cs 3 Cu 2 I 5 nanocrystals powder as phosphor, which exhibit good working stability with a half-lifetime over 300 h. Besides, the Cs 3 Cu 2 I 5 nanocrystals solution is also utilized as fluorescent ink, and the printed patterns can maintain anti-counterfeiting features even after treatment by heating and long-term environmental storage, indicating the robustness of these Cs 3 Cu 2 I 5 nanocrystals for potential anti-counterfeiting application.
研究领域:
材料科学
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光学工程
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Nature Nanotechnology
·
2025
·
IF 34.9
Dong Jianchao,Zhao Bin,Ji Huiyu,Zang Ziang,Kong Lingmei,Chu Chunshuang,Han Dongyuan,Wang Jie,Fu Yuhao,Zhang Zi-Hui,Yang Yingguo,Zhang Lijun,Yang Xuyong,Wang Ning
Despite substantial advances in green and red metal halide perovskite light-emitting diodes (PeLEDs), blue PeLEDs, particularly deep-blue ones (defined as Commission International de l’Eclairage y coordinate (CIE y ) less than 0.06) that meet the latest Rec. 2020 colour gamut standard, lag dramatically behind owing to a severe phase segregation-induced electroluminescent spectral shift and low exciton utilization in broadened bandgap perovskite emitters. Here we propose a multivalent immobilization strategy to realize high-efficiency and spectrally stable deep-blue PeLEDs by introducing a polyfluorinated oxygen-containing molecule. Systematic experiments and extensive 5,000 fs ab initio molecular dynamics simulations reveal that a crucial role of the multivalent effect stemming from three kinds of interaction of hydrogen bond (F···H–N), ionic bond (F–Pb) and coordination bond (C=O:Pb) with perovskite is to synergistically stabilize the perovskite phase and enhance exciton radiative recombination. The resultant exciton concentration and exciton recombination rate of the deep-blue perovskite emitter are increased by factors of 1.66 and 1.64, respectively. In this context, our target PeLEDs demonstrate a peak external quantum efficiency of up to 15.36% at a deep-blue emission wavelength of 459 nm and a half-lifetime of 144 min at a constant current density of 0.45 mA cm − 2 . Moreover, the deep-blue PeLEDs maintain a constant spectrum peak with CIE chromaticity coordinates of (0.136, 0.051) under a steady driving current for 60 min.
研究领域:
材料科学
·
光电技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2022
·
IF 9.224
Lin Liu,Shanshan Peng,Lei Fu,Yuxuan Guo,Xia Sun,Liang Song,Junpeng Shi,Yun Zhang
Since the strong blue light from the conventional blue chip has negative effects on human health, near-ultraviolet (n-UV) white light-emitting diodes (W-LEDs) have been widely studied. However, the photoluminescence spectrum generated by tricolor (blue, green, and red) phosphors contains a notable cavity in the deep-blue region (400–430 nm), which reduces the color quality. In this work, we report a novel series of narrow-band deep-blue-emitting phosphors with strong n-UV excitation, Ln2Si2O7:Bi3+ (Ln = Gd, Y, Lu, Sc), and realize the tuning of emission from 422 to 403 nm via cationic substitution, which bridges the deep-blue gap. All of these phosphors are effectively excited by n-UV radiation at approximately 370 nm and exhibit narrow-band deep-blue emission with a full width at half-maximum (FWHM) < 50 nm. Among them, Sc2Si2O7:Bi3+ generates 403 nm deep-blue emission with a 38 nm FWHM under 372 nm n-UV excitation, with high luminescence intensity and excellent thermal stability. Finally, 365 nm n-UV-pumped phosphor-converted (pc) W-LED devices are fabricated by combining Sc2Si2O7:Bi3+ and commercially available phosphors, and they have a high color-rendering index (Ra) of 95.4 and a low correlated color temperature (CCT) of 3736 K. This result suggests that these phosphors have potential applications in full-spectrum warm white lighting.
研究领域:
材料科学
·
光学工程
·
照明技术
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2024
·
IF 18.5
Jiaqi Li,Yingyi Nong,Jisong Yao,Leimeng Xu,Zhi Yang,Shalong Wang,Jizhong Song
Metal halide perovskite quantum dot-based light-emitting diodes (QLEDs) have garnered considerable attention for realizing wide color gamut displays. Despite the breakthrough achieved in sky-blue perovskite QLEDs, it is still challenging to realize efficient Rec. 2020-blue perovskite QLEDs. Herein, a triphenylamine derivative-tailored hole transport layer (HTL) strategy is proposed for improving hole injection in deep-blue perovskite QLEDs. The hole mobility of the tailored HTL (T-HTL) is enhanced by ≈3.5 times compared to the pristine HTL (P-HTL) by mixing the 4,4′-cyclohexylidenebis [N, N-bis(p-tolyl) aniline] (TAPC) into poly [bis(4-phenyl) (4-butylphenyl) amine] (Poly-TPD), and the highest occupied molecular orbital (HOMO) level of T-HTL is shifted down by 0.11 eV compared to P-HTL, facilitating hole injection into the emitting layer. The resulting deep-blue perovskite QLEDs exhibit an external quantum efficiency of 11.0% at 465 nm, meeting the Rec. 2020 standard and representing the state-of-the-art deep-blue perovskite QLEDs. Theoretical calculations and experimental results demonstrate that the enhanced hole transport capacity of the T-HTL is attributed to the intermolecular π–π stacking between TAPC and Poly-TPD. Other triphenylamine derivatives can also tailor the hole transport capacity and improve device performance, which demonstrates the universality of the proposed strategy.
研究领域:
材料科学
·
光电工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Miao Zhang,Jingyun Zhang,Lei Gu,Qingmei Su,Pengpeng Qiang,Yingjun Yang,Shuakai Ding,Tanxin Yao,Xiuhai Zhang,Gaohui Du,Bingshe Xu,Hongyue Wang
Metal-halide perovskite nanocrystals (NCs) are one of the most promising emitters for the application of display and nanolight sources. The full width at half-maximum (FWHM) of photoluminescence (PL) emission is essential for color purity, which however remains a difficulty to further reduce the FWHM of the perovskite NCs at room temperature. Here, we show the quasi-sphere perovskite NCs with narrow PL emission at a deep-blue wavelength of ∼430 nm; its PL FWHM reaches ∼11 nm at room temperature, owing to the monodispersion in size distribution as well as the symmetric quasi-sphere morphology of NCs releasing the fine structure splitting-induced inhomogeneous broadening. Through regulating A cations with respect to the ratio of FA (or MA)-to-Cs and Cs-to-Pb, the PL emission of the NCs could be tuned from ∼505 to ∼430 nm combined with varied morphologies from large cube to small quasi-sphere. Such spectroscopic and morphological discrepancies are supposed to be attributed to the different crystalline kinetics that is strongly dependent on the synthetic condition. To be specific, in the case of increasing FA (or MA)-to-Cs, the growth rate of CsPbBr3 and FAPbBr3 (or MAPbBr3) perovskites is determined by the reactivity of transient species, while in the case of decreasing the Cs-to-Pb ratio, the growth rate of perovskites is slowed down by the serious reduction of Cs+ in the precursor. This study provides an effective strategy to adjust the emission across from green to deep-blue color and promotes the perovskite NCs with a narrow FWHM, and tunable PL emission facilitates in application of optoelectronic devices.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2020
·Vol. 31
·期 6
·2006736
·
IF 16.836
Yang Shen,Kong-Chao Shen,Yan-Qing Li,Minglei Guo,Jingkun Wang,Yongchun Ye,Feng-Ming Xie,Hao Ren,Xingyu Gao,Fei Song,Jian-Xin Tang
Perovskite light-emitting diodes (PeLEDs) are emerging candidates for the applications of solution-processed full-color displays. However, the device performance of deep-blue PeLED still lags far behind that of their red and green counterparts, which is largely limited by low external quantum efficiency (EQE) and poor operational stability. Here, a facile and reliable crystallization strategy for perovskite grains is proposed, with improved deep-blue emission through rational interfacial engineering. By modifying the substrate with potassium cation (K + ) as the supplier of heterogeneous nucleation seeds, the interfacial K + -guided grain growth is realized for well-packed perovskite assemblies with high surface coverage and the controlled crystal orientation, leading to the enhanced radiative recombination and hole-transport capabilities. Synergistical boost in device performance is achieved for deep-blue PeLEDs emitting at 469 nm with a peak EQE of 4.14%, a maximum luminance of 451 cd m –2 , and spectrally stable color coordinates of (0.125, 0.076) that matches well with the National Television System Committee (NTSC) standard blue.
研究领域:
材料科学
·
光电技术
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Yanfeng Chen,Meng Nan,Yanxing He,Shuang Lu,Wei Shen,Gang Cheng,Shufen Chen,Wei Huang
During the synthesis of deep-blue perovskite quantum dots (PQDs), they generally emerge as a two-dimensional byproduct with poor yield and low photoluminescence quantum yield (PLQY) due to amine ligand enrichment-induced abundant surface defects. Herein, we provide a colloidal synthesis method to prepare deep-blue CsPbBr3 PQDs in a green nontoxic solvent via strategic Z-type ligand engineering. Z-type ligands of zinc octanoate enable the formation of robust coordination bonds with surface bromide ions of PQDs, maintaining acid–base equilibrium and reducing excess amine enrichment on the PQDs surface. Consequently, homogeneous and monodispersed PQDs with improved PLQY of 73% are successfully synthesized, achieving efficient deep-blue LEDs with a peak EQE of 5.46%, a maximum luminance of 847.6 cd/m2, and an operational half-lifetime of 14 min. The devices exhibit color coordinates of (0.137, 0.049), closely approximating the Rec. 2020 blue standard. Our work offers a potentially eco-friendly and viable route for realizing high-performance LEDs in the deep-blue region.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Xin Zheng,Changting Wei,Shichen Yuan,Daqing Zhang,Xiansheng Li,Xin Luo,Weiling Lu,Bo Xu,Jing Huang
Hole-injection layers (HILs) play crucial roles in enhancing the performance of perovskite light-emitting diodes (PeLEDs) by lowering the energy barrier between the anode and the hole-transport layer (HTL). However, the commonly employed HIL, poly( 3 , 4 -ethylenedioxythiophene): polystyrene sulfonic acid (PEDOT: PSS) has notable drawbacks, such as extreme acidity and susceptibility to corrosion, which severely hampers device efficiency and stability. Herein, a self-assembled monolayer (SAM)-[ 2 -( 9H -Carbazol- 9 -yl) ethyl] phosphonic acid (2PACz) instead of PEDOT: PSS was employed in PeLEDs, which could reduce the negative impacts on neighboring perovskite sites and indium tin oxide electrodes. To obtain favorable energy level alignment between 2PACz and the perovskite layer, poly( 9 -vinylcarbazole) (PVK) was introduced as an indispensable HTL. Consequently, the 2PACz/PVK-based deep-blue PeLEDs exhibit a lower turn-on voltage of 3.20 V, and a peak external quantum efficiency of 4.42 % at 467 nm, which is a threefold improvement over the control devices. This impressive performance boost can be attributed to the reduction in interfacial defects and the improved balance of carrier injection, leading to more efficient light emission. Our study not only introduces an innovative and cost-effective HIL solution for PeLEDs but also provides valuable insights and guidance for the development of highly efficient and stable PeLEDs in the future.
研究领域:
材料科学
·
光电子学
·
光子学
·
半导体器件
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）