APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Cheng-Long Shen,Jin-Hao Zang,Qing Lou,Guang-Song Zheng,Meng-Yuan Wu,Yang-Li Ye,Jin-Yang Zhu,Kai-Kai Liu,Lin Dong,Chong-Xin Shan
Carbon nanodots (CDs) are emerging as low toxic chemiluminescent (CL) materials for new-generation cold lighting and bioimaging technology due to their tunable and efficient emissions. Nevertheless, continuous progress and efforts are still needed to improve the luminance and lifetime of the CL CDs. Here, CL quenching is observed in the CD-peroxyoxalate-hydrogen peroxide system, resulting from the water-induced aggregation and blocking effect of the electron exchange between the CDs and energetic intermediate produced in the CL reaction. A surface chemical regulation strategy is first introduced to improve the CL performance of CDs. Optimized the capped ligand species and chain length, the CDs modified by n-butylamine exhibit a CL quantum yield of 1.15 × 10 –2 einsteins mol −1 and maximal luminance of 5.11 cd m −2 , which is about 5- and 13-fold higher than the initial CDs and comparable with commercially available Rhodamine B. The enhanced performance can be explained by the decreased electron capture from water molecules generated due to the decomposition of hydrogen peroxide in the CL process.
研究领域:
材料科学
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化学工程
·
生物成像
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DOI
高影响因子
Journal of Materiomics
·
2025
·
IF 9.6
Rundong Tian,Tianliang Zhou,Rong-Jun Xie
Laser-remote activated phosphor (LARP) converted solid state lighting is now developing towards high power density and super-brightness, and phosphor ceramic converters with high efficiency, high thermal conductivity, acceptable transmittance and suitable spectra are thus required. Y 3 Al 5 O 12 :Ce (YAG:Ce)-based ceramics are promising color converters to produce white light with a color temperature of 6000 K for vehicle headlamps, but the brightness and luminous efficiency are not well optimized. In this work, two series of Al 2 O 3 -YAG:Ce and Al 2 O 3 -(Gd,Y)AG:Ce transparent ceramics were fabricated by vacuum sintering, and their microstructure, thermal and optical properties were controlled by changing the Ce 3+ or Al 2 O 3 content as well the thickness of the ceramics. Both Al 2 O 3 -Y 2.925 Al 5 O 12 :Ce 0.0175 (AY0.0175) and Al 2 O 3 -(Gd 0.1 Y 2.89 )Al 5 O 12 :Ce 0.01 (AGY) ceramics containing 70% (in mass) Al 2 O 3 show a luminance saturation threshold of 30.3 W/mm 2 and 38.4 W/mm 2 , enabling to produce white light with a color temperature of 6000 K, luminous flux of 1928 lm and 3101 lm, luminous efficiency of 135.0 lm/W and 161.1 lm/W when pumped by blue laser diodes, respectively. This work provides a solution to finely control the composition, microstructure, and optical properties of transparent ceramics for super-high brightness laser-driven solid-state lighting.
研究领域:
材料科学
·
光学工程
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Rundong Tian,Shuxing Li,Tianliang Zhou,Rong-Jun Xie
The significant expansion of the luminescent area on transparent phosphor ceramics relative to laser spot limits the laser lighting operating in transmission configuration to achieve both high luminous flux and high brightness. Herein, by introducing polymethyl methacrylate (PMMA) as a pore-forming agent during the secondary forming process and employing a secondary sintering process under an inert protective atmosphere, we successfully fabricated a dual-ceramic converter. This converter consists of an outer porous ceramic (68wt%Al 2 O 3 -(Gd 0.1 ,Y 2.90 )AG) and an inner small-sized transparent phosphor ceramic (70wt%Al 2 O 3 -(Gd 0.1 ,Y 2.89 )AG: 0.01 Ce). Benefiting from the miniaturization of the phosphor ceramic and the enhanced cavity effect and thermal conduction provided by the high-refractive-index porous ceramic, the actual luminescent area was reduced from 7.75 mm 2 to 1.73 mm 2 , achieving a luminous exitance of 1969 lm/mm 2 – a 607% enhancement over conventional phosphor ceramics – while delivering 3407.6 lm white light of 6000 K. This work establishes a universal strategy for ceramic-based color converters through microstructural engineering, resolving the critical flux-brightness trade-off in high-power solid-state lighting.
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高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2020
·Vol. 30
·期 48
·2005990
·
IF 16.836
Chenghao Bi,Jingcong Hu,Zhiwei Yao,Yue Lu,David Binks,Manling Sui,Jianjun Tian
Bright red emission (620–650 nm) from perovskite light-emitting diodes (PeLEDs) is usually achieved via a composition including both bromine and iodine anions, which results in poor performance and stability due to phase separation under operating conditions. Here a large-scale ligand-assisted reprecipitation method is devised with nonpolar solvent that enables the fabrication of CsPbI 3 nanowire clusters, emitting at 600 nm. The blue-shift of this emission relative to that of bulk CsPbI 3 (≈700 nm) is attributed to quantum confinement in nanowires. The growth of the nanowires is along the [011] crystal direction and is vacancy driven, resulting in the healing of surface defects and thereby a high photoluminescence quantum yield of 91%. The clusters with ultralow trap density show remarkable structural and environmental stability. PeLEDs based on these clusters exhibit an external quantum efficiency of 6.2% with Commission Internationale de l'Eclairage coordinates of (0.66, 0.34), and record luminance of 13 644 cd m −2 of red electroluminescence. The half-lifetime under an accelerated stability test is 13.5 min for an unencapsulated device in ambient conditions operating at an initial luminance of 11 500 cd m −2 , which corresponds to an estimated half-lifetime of 694 h at 100 cd m −2 based on acceleration factor obtained by experimental testing.
研究领域:
材料科学
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纳米科技
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光电子学
·
半导体器件
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发光材料
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晶体工程
·
光电转换
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DOI
高影响因子
Advanced Science
·
2022
·Vol. 9
·期 22
·2201844
·
IF 17.521
Zong-Tao Li,Hong-Wei Zhang,Jia-Sheng Li,Kai Cao,Ziming Chen,Liang Xu,Xin-Rui Ding,Bin-Hai Yu,Yong Tang,Jian-Zhen Ou,Hao-Chung Kuo,Hin-Lap Yip
Tandem structures with different subpixels are promising for perovskite-based multicolor electroluminescence (EL) devices in ultra-high-resolution full-color displays; however, realizing excellent luminance- and color-independent tunability considering the low brightness and stability of blue perovskite light-emitting diodes (PeLEDs) remains a challenge. Herein, a bright and stable blue gallium nitride (GaN) LED is utilized for vertical integration with a green MAPbBr 3 PeLED, successfully achieving a Pe-GaN tandem LED with independently tunable luminance and color. The electronic and photonic co-excitation (EPCE) effect is found to suppress the radiative recombination and current injection of PeLEDs, leading to degraded luminance and current efficiency under direct current modulation. Accordingly, the pulse-width modulation is introduced to the tandem device with a negligible EPCE effect, and the average hybrid current efficiency is significantly improved by 139.5%, finally achieving a record tunable luminance (average tuning range of 16631 cd m −2 at an arbitrary color from blue to green) for perovskite-based multi-color LEDs. The reported excellent independent tunability can be the starting point for perovskite-based multicolor EL devices, enabling the combination with matured semiconductor technologies to facilitate their commercialization in advanced display applications with ultra-high resolution.
研究领域:
材料科学
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光电技术
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显示技术
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DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2021
·
IF 5.302
Jian Xu,Lanjie Wang,Wen Gu,Zhi Jiang,Xinrong Chen,Baofu Hu,Baoli Du,Haipeng Ji,Carsten Dam-Hansen,Ole B. Jensen
One major benefit of laser lighting is the possibility to achieve very high luminance. In phosphor-converted laser lighting systems, a blue (pump) laser can be focused into a very small spot. However, after excitation of the phosphor, the white-light-emitting area usually increases considerably, which reduces the luminance parameter substantially. Herein, we design and investigate a highly scattering YAG:Ce/glass composite film with a porous microstructure. Both the glass/phosphor interfaces and the introduced pores act as scattering centers, which can confine the emission area effectively. The relationship between the spot size and the microstructure (porosity, phosphor-particle size, thickness) is elucidated. Under excitation with blue laser , the composite film shows a uniform white-light emission with high luminous efficacy (230 lm/W) and high saturation threshold (> 40 W/mm 2 ), thus achieving a high luminous exitance of ∼1239 lm/mm 2 . With above excellent properties, the designed composite films show great potential for use in high-luminance laser lighting.
研究领域:
光学工程
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光子学
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固态照明
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材料科学
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DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2022
·
IF 9.224
Shuyang Bao,Yueyuan Liang,Liansheng Wang,Luhan Wang,Li Xu,Yu Wang,Xiaojuan Liang,Weidong Xiang
Solid laser lighting with high photoelectric conversion efficiency and compact size has been increasingly vital in lighting applications. Extensive research has been conducted to obtain high-quality color converters for application to high-power and high-luminance laser lighting. Currently, Y3Al5O12:Ce3+ phosphor in glass (Ce:PiG) and Y3Al5O12:Ce3+ phosphor-in-glass film (Ce:PiF) possessing high efficiency, low cost, easy fabrication, and controllable chromaticity are becoming the most mainstream research directions. In this study, by modifying the glass particle size and sintering temperature, investigating the relevant host glass, and so forth, high-performance Ce:PiG was developed through a one-step co-sintering technology. It possesses a high internal quantum efficiency, approaching 100% of the original phosphors (92.5%). The luminous efficacy (LE) of the Ce:PiG was 240 lm/W at 2.18 W/mm2 under 450 nm blue laser diode (LD) excitation, which is the best result yet reported. Furthermore, to enhance the laser saturation threshold, the fabricated Ce:PiF relying on a sapphire substrate can withstand an 8 W/mm2 blue incident power density. The obtained sample can even reach an LE of 251.5 lm/W, which is an obvious improvement to Ce:PiG. In addition, the result, an LD module combined with the sample that meets the standard white light source, indicates that this work has good prospects for white laser lighting.
研究领域:
光电技术
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材料科学
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照明工程
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产品关联
DOI
高影响因子
Laser & Photonics Reviews
·
2019
·Vol. 13
·期 10
·1900147
·
IF 9.056
Peng Zheng,Shuxing Li,Ran Wei,Le Wang,Tian-Liang Zhou,Yi-Rong Xu,Takashi Takeda,Naoto Hirosaki,Rong-Jun Xie
Robust ceramic color converters withstanding strong laser irradiations have recently drawn great attention for laser-driven white lighting. However, the local emission within the incident laser spot usually expands to the whole surface area of the ceramics, which definitely makes it hard to achieve white light with high luminance and high directionality. Herein, a new strategy is proposed to solve the problem by elaborately introducing uniform spherical pores (diameter of ≈2 µm) into the phosphor ceramics with controlled contents from 8 to 24.6 vol%. The well-distributed pores, acting as light scattering centers, enable reduction of the luminescent spot size greatly but without any losses in conversion efficiency. By using the high-scattering ceramic color converters with 15% porosity, the light spot diameter is decreased by 46% and the central illuminance is increased by 156%. Moreover, laser-driven white light with an enhanced beam directionality and uniformity is also achieved. A superhigh luminous flux of 7199 lm is realized by using this promising color converter in a rotary mode. The designed high-scattering ceramics with controllable microstructures show great potential for use in extra-high luminance laser-driven lighting and projection.
研究领域:
材料科学
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光学工程
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产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2019
·Vol. 7
·期 37
·11449-11456
·
IF 6.641
Yirong Xu,Shuxing Li,Peng Zheng,Le Wang,Shihai You,Takashi Takeda,Naoto Hirosaki,Rong-Jun Xie
To achieve extra-high brightness laser lighting, the bottleneck of thermally-induced luminance saturation that phosphor materials (i.e., color converters) usually suffer from under high power density laser excitation must be broken. However, the mechanisms for thermal saturation are not fully understood yet. Here, thermal saturation of typical Ce3+-doped garnet phosphor ceramics was systematically investigated by considering the balance among heat generation, dissipation and resistance of color converters. With increasing Ce concentration (0.0167 → 0.433%), the thermal saturation threshold decreases due to more heat generation (i.e., 3.97 → 6.73 W at an incident laser power of 6.73 W). A tunable saturation threshold (2–49 W mm−2) was observed by a chemical substitution strategy because of the difference in the thermal resistance and heat generation. The sample thickness exerts a complex influence on the saturation threshold accompanied by increased heat generation and enhanced heat dissipation corroborated by a broader temperature distribution curve. Based on these investigations, a high-flux white light of 2347.9 lm is obtained with robust YAG:Ce ceramics irradiated with a high power density of 31.94 W mm−2. Moreover, a promising green color converter able to withstand a blue laser power density of 49 W mm−2 was discovered for laser displays with an output luminous flux of 3967.3 lm. This work provides a principle to design and/or select phosphor materials with high thermal saturation thresholds, thus accelerating the rapid development of laser-driven lighting and displays.
研究领域:
光学材料
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激光技术
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材料科学
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产品关联
DOI
高影响因子
Laser & Photonics Reviews
·
2025
·Vol. 19
·期 12
·2402164
·
IF 10
Fengyang Ma,Kaixin Liu,Zhongyao Yan,Liang Yu,Yanru Yang,Wuyan Zhao,Feilong Wang,Yaohua Li,Shuyu Zhang,Songyou Wang,Jian Sun,Ming Lu
Silicon (Si) light source has profound significance in monolithic integrated Si photonics. However, its luminance remains too low to meet practical use that usually requires > 10000 cd m⁻ 2 . Here, an all-inorganic Si nanocrystal (SiNC) white light-emitting diode (WLED) with a continuous emission spectrum spanning ≈400–900 nm in wavelength, is reported. The architecture of the WLED comprises front electrode of Ag grids and transparent-conducting-oxide/electron transport layer (ETL) of ZnO/front charge confinement layer (CCL) of SiO 2 /active layer of low-resistivity SiNC composite thin film/rear CCL of SiO 2 /hole transport layer (HTL) of MoO 3 /textured p-Si substrate/rear electrode of aluminum/heat radiator. The main procedures for achieving high luminance here include combined applications of high-pressure ammonia passivation of the active layer, which enhances its photoluminescence quantum yield significantly, and texturing of p-Si substrate, which boosts the light extraction and charge injection effectively. With an optimized combination of passivation and texturing, luminance of 10751 cd m⁻ 2 is achieved with external quantum efficiency (EQE) of 0.26%. After a Peltier cooler is further applied, luminance of 12363 cd m⁻ 2 is attained with EQE of 0.30%. Following further technical iterations, this highly bright SiNC WLED shall find applications in monolithic integrated Si photonics and even Si general lighting.
研究领域:
材料科学
·
光学
·
电子工程
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产品关联
DOI
高影响因子
ACS Nano
·
2022
·
IF 18.027
Huanyu Zhang,Tingxiu Yu,Chaoqiang Wang,Ruofei Jia,Azhar Ali Ayaz Pirzado,Di Wu,Xiujuan Zhang,Xiaohong Zhang,Jiansheng Jie
Micro-/nanosized organic–inorganic hybrid perovskite single crystals (SCs) with appropriate thickness and high crystallinity are promising candidates for high-performance electroluminescent (EL) devices. However, their small lateral size poses a great challenge for efficient device construction and performance optimization, causing perovskite SC-based light-emitting diodes (PSC-LEDs) to demonstrate poor EL performance. Here, we develop a facile liquid-insulator bridging (LIB) strategy to fabricate high-luminance PSC-LEDs based on single-crystalline CH3NH3PbBr3 microflakes. By introducing a blade-coated poly(methyl methacrylate) (PMMA) insulating layer to effectively overcome the problems of leakage current and possible short circuits between electrodes, we achieve the reliable fabrication of PSC-LEDs. The LIB method also allows us to systematically boost the device performance through crystal growth regulation and device architecture optimization. Consequently, we realize the best CH3NH3PbBr3 microflake-based PSC-LED with an ultrahigh luminance of 136100 cd m–2 and a half-lifetime of 88.2 min at an initial luminance of ∼1100 cd m–2, which is among the highest for organic–inorganic hybrid perovskite LEDs reported to date. Moreover, we observe the strong polarized edge emission of the microflake-based PSC-LEDs with a high degree of polarization up to 0.69. Our work offers a viable approach for the development of high-performance perovskite SC-based EL devices.
研究领域:
材料科学
·
光电子学
·
纳米技术
·
半导体器件
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DOI
高影响因子
npj Flexible Electronics
·
2024
·Vol. 8
·期 1
·1-13
·
IF 12.3
Lu Ya,Chen Yuanyuan,Sun Haoyu,Deng Fang,Mei Changtong,Xu Xinwu,Wu Qinglin,Xiao Huining,Yue Yiying,Han Jingquan
Electroluminescent (EL) devices are of great significance for expanding the application range of optoelectronics. However, the realization of EL devices with environment-tolerance, stretchability, mechanical cycling stability, self-adhesion, biocompatibility, and high dielectric constant still remains a challenge. Herein, a type of EL device with enhanced comprehensive performances composing of a chlorinated barium titanate/phosphor/polydimethylsiloxane (Cl-BT/phosphor/PDMS) luminescent layer sandwiched between two silver nanowire-cellulose nanocrystal with II crystalline allomorph/Triton X-100 modified polydimethylsiloxane (AgNW-CNC II/TX-PDMS) electrodes fabricated through a full solution-processing strategy is proposed. Environmentally-friendly CNC II with high transmittance acts as an antioxidant, dispersant and film-former for AgNWs. The hydrophilic modification of TX to PDMS imparts the electrodes with self-adhesion, high stretchability, as well as strong interfacial bonding between TX-PDMS and AgNW-CNC II. The electrodes achieve skin-like modulus by adjusting TX content, endowing the EL devices with a high compliance (186 kPa of Young’s modulus). The luminescent layer with Cl-BT exhibits a high dielectric constant (19) and luminance (up to 72 cd m −2 ). The assembled EL device with excellent cyclic stability (luminance retention 85% after 400 cycles), durability (luminance retention >94% after 400 min) and stretchability (88% luminance at 200% strain) can work properly at broad temperatures (−20 ~ 70 °C) and underwater. This biocompatible and self-adhesive EL device demonstrates great potential for implantable biomedical devices and wearable displays under harsh environments.
研究领域:
材料科学
·
生物医学工程
·
柔性电子学
✓ 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）