OPTICAL MATERIALS
·
2020
·
IF 2.779
Lu Chen,Fang Lei,Haohong Chen,Luqiao Yin,Ding Zhou,Ying Shi,Teng Ma
A novel Eu 3+ doped SiO 2 -B 2 O 3 -Al 2 O 3 -CaO-Na 2 O based borosilicate glass was designed to embed YAG: Ce for PiGs. It exhibits intense Eu 3+ red emission with the average decay times of 6.8 μs and has the thermal conductivity of about 0.9 W/(mK) (five times that of silicone resin). The doped Eu 3+ is over 10 mol% without any concentration quenching. The PiGs show variable decay time of Ce 3+ , which results from the tunable interface defects explained by the pseudo-solid solubility mechanism. The color of the WLEDs changes from cool white (6004 K) to warm white (3799 K) with more yellow emission added. The obtained maximal luminous efficiency and color rendering index are about 68 lm/W and 78, respectively. The anti-thermal quenching power of the PiGs is three times that of PiS based on the luminescent reduction. The PiG system can be used potentially for resin-free high power WLEDs.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Xiao-Fei Wang,Gui-Gen Wang,Jia-Bing Li,Zheng Liu,You-Xiao Chen,Long-Fei Liu,Jie-Cai Han
Herein we first report new chlorine-doped graphene quantum dots (Cl-GQDs) that can be used in solid-state white-light-emitting diodes (WLEDs). The Cl-GQDs with a mean size of 1.53 nm are obtained by one-step hydrothermal method using β-cyclodextrin and hydrochloric acid as the source materials. The PL emission spectra of the Cl-GQDs show an excitation-wavelength-dependent behavior in the range from 300 to 380 nm excitation. Under UV irradiation, the Cl-GQDs can direct emit white light. Given that they are worth using in light-conversion, Cl-GQDs embedded solid composite film (Cl-ESCF), based on silicon resin as host material, is successfully fabricated by solution-processing approach. The freestanding Cl-ESCF has high transparency and flexibility, excellent photostability and temperature resistance, and retains its optical properties in the solid state. In order to realize its potential, the Cl-ESCF converted remote UV-pumped WLED is demonstrated. The results verify that the Cl-GQDs can be homogeneously dispersed within solid matrix without obvious aggregation so that a uniform and defect-free natural white light can be obtained. In addition, our WLED possesses favorable white-light characters with the CIE of (0.33, 0.34), moderate CCT of 5653 K, and high CRI of 87.6, as well as good color and LED stability. This single-phase rare-earth-free white-luminescent Cl-GQDs may be not only expected to prevent the drawbacks of multicolor phosphors, thereby generating high-quality white emission, but also identified to be a green alternative for conventional emitters.
研究领域:
材料科学
·
纳米技术
·
光电
·
光子学
✓ 已验证
产品关联
DOI
高影响因子
NANOTECHNOLOGY
·
2019
·Vol. 30
·期 46
·465201
·
IF 3.399
Congcong Wang,Dingke Xue,Xinyu Shen,Hua Wu,Yu Zhang,Haining Cui,William W Yu
Perovskite white light-emitting devices (WLEDs) without intercalation layers have not been achieved due to the ion exchange. Although the intercalation layers prevent ion exchange between perovskite nanocrystals (NCs), it also creates a new problem of charge imbalance and the structure becomes more complex. In this study, blue emitting ZnCdS/ZnS NCs with high quantum yield and stability are introduced to work with the yellow emission from CsPb(Br/I)3 perovskite NCs for WLEDs. The WLEDs are constituted of ITO/ZnO/PEI/ZnCdS/ZnS NCs/CsPb(Br/I)3 NCs/TCTA/MoO3/Au. This design avoids ion exchange between different perovskites NCs, and realizes white light emission by simple fabrication. As a result, we achieved the white light coordinates of (0.34, 0.34) and a correlated color temperature of 5153 K.
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
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2026
·
IF 4.8
Xiumei Guo,Yanzhi Zhang,Xingyang Peng,Heng Yu,Chengjun Pan,Ruirui Cui,Xiang Guo
The development of high-efficiency and thermally stable phosphors is crucial for improving the color rendering index (CRI) of near-ultraviolet (n-UV) pumped white light-emitting diodes (WLEDs). In this work, a novel orange-red emitting phosphor La 2 SrGa 4 Si 2 O 14 :Sm 3+ was successfully synthesized via a [Sr 2+ -Si 4+ ] co-substitution strategy to optimize the lattice of the traditional La 3 Ga 5 SiO 14 . Detailed structural analyses confirmed the successful substitution and phase purity. Excited by n-UV light at 402 nm, the phosphor exhibited a prominent emission peak at 600 nm, with an optimal doping concentration of 3 mol%. The material exhibits acceptable thermal stability, retaining 74% of its initial emission intensity at 423 K, together with an internal quantum efficiency of 32.3%, which is comparable to those of several reported Sm 3+ -activated silicate phosphors. When integrated into WLED devices with blue and green phosphors, it yielded high-quality warm white light with a low correlated color temperature of 4680 K and an exceptionally high CRI of 93.2, which represents a noticeable improvement compared with a commercial blue-chip + YAG:Ce WLED measured under identical experimental conditions. Furthermore, by utilizing the unique thermal response characteristics of Sm 3+ transitions, this material was explored for optical temperature sensing, achieving a maximum relative sensitivity of 2.06% K −1 . These results indicate that La 2 SrGa 4 Si 2 O 14 :Sm 3+ is a potential multifunctional material for high-CRI solid-state lighting and non-contact temperature sensing.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
·
2023
·
IF 4.6
Dehai Liang,Zhe Sun,Shirong Lu,Jinrong Zhao,Yong Zhou,Kang An,Zhigang Zang
Lead-free metal halides (LMHs) have recently attracted numerous attention in solid-state lighting due to their unique structures and outstanding optoelectronic properties. However, conventional preparation processes with the utilization of toxic organic solvents and high temperatures seem to impede commercial applications of LMHs. In this work, we successfully synthesize Cu+-based metal halides (TMA)3Cu2Br5–xClx (TMA: tetramethylammonium) with high photoluminescence quantum yields (PLQYs) via a solvent-free mechanical grinding method. By changing the ratio of halide ions (Cl– and Br–) in precursors, the emission wavelength of the prepared (TMA)3Cu2Br5–xClx can be tuned from 535 to 587 nm, which are employed as emitters in the fabrication of white-light-emitting diodes (WLEDs). The achieved WLEDs exhibit a high color rendering index value of 84 and standard Commission Internationale de l’Éclairage (CIE) coordinates of (0.324, 0.333). This feasible and solvent-free preparation strategy not only promotes the mass production of LMHs but also highlights the promising potential for efficient solid-state illumination.
研究领域:
材料科学
·
光电
·
固态照明
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Yonghui Xu,Liang Zhang,Shuwen Yin,Xiudi Wu,Hongpeng You
Despite significant progress has been made in the luminescent materials for white light emitting diodes (WLEDs), it is still desirable to develop novel highly efficient phosphors with appropriate excitation and high visible emission for high color rendering WLEDs. In this study, we report a novel phosphor BaGa 2 Si 2 O 7 :Ce 3+ ,Tb 3+ (BGSO:Ce 3+ ,Tb 3+ ) with highly effective green luminescence. BGSO:Ce 3+ ,Tb 3+ phosphor represents a broad excitation band in the range of 300–400 nm and intense emission at approximately 542 nm with a high photoluminescence quantum efficiency of 76.4%. The structure, luminescence, and energy transfer from the Ce 3+ and Tb 3+ ions were investigated in detail. Moreover, the incorporation of Na + or K + ions into BGSO:Ce 3+ ,Tb 3+ for charge compensation can improve the emission intensity and thermal stability. Moreover, a near ultraviolet (n-UV) pumped prototype WLED device was fabricated and it exhibited bright warm-white light with CIE chromaticity coordinates of (0.3561, 0.3344), high color-rendering index (Ra=90.4), and low CCT (3330 K) upon 20 mA driving current. This work provides a new strategy to develop high-quality solid-state LED phosphors.
研究领域:
材料科学
·
光学工程
·
固体物理
·
发光材料
·
半导体器件
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2026
·
IF 6.7
Xiumei Guo,Chengjun Pan,Heng Yu,Nian Wang,Ruirui Cui,Xiang Guo
To address the practical need for high-efficiency red-emitting phosphors in near-ultraviolet (n-UV) chip-powered white light-emitting diodes (WLEDs), Eu 3+ -doped Ca 3 Zr 2 Ga 2 SiO 12 (CZGSO: x Eu 3+ ) red phosphors were prepared using a conventional high-temperature solid-state reaction method. Subsequently, the optimized phosphor was incorporated with commercial blue and green phosphors to develop a n-UV excited white light-emitting diode (WLED) prototype. A systematic investigation was conducted on the crystal structure, photoluminescence behavior of the phosphors, as well as the practical performance of the device. The findings reveal that Eu 3+ ions successfully occupy the Ca 2+ crystallographic sites within the CZGSO matrix, and all samples retain a single-phase cubic garnet structure with homogeneously distributed constituent elements. The Eu 3+ ions are located in a highly asymmetric local crystal field environment. Under 393 nm excitation, the phosphor exhibits intense red emission centered at 610 nm, dominated by electric dipole transitions, showing good spectral matching with n-UV chips. The optimized composition, CZGSO:0.25Eu 3+ , demonstrates excellent luminescence performance, with a lifetime of 2.19 ms and an IQE of 70.1%. Additionally, this phosphor shows good thermal stability, retaining 85.1% of its initial emission intensity at 423 K, and possesses an activation energy of 0.18 eV. A WLED prototype constructed using this phosphor emits stable white light, achieving a correlated color temperature of 4989 K and a color rendering index of 88.2. Moreover, the spectral profile and color performance remain stable over a wide current range of 100–700 mA. These results suggest that CZGSO:Eu 3+ serves as a highly promising red-emitting phosphor for n-UV pumped WLEDs, representing a competitive option for advanced solid-state lighting.
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Xiumei Guo,Yanzhi Zhang,Xingyang Peng,Ruirui Cui,Jun Zhang,Xiang Guo
The demand for efficient plant lighting has driven the search for high-performance blue-emitting phosphors, as blue light (400–500 nm) is crucial for photosynthesis, protein synthesis, and biomass accumulation. However, existing phosphors often lack optimal spectral coverage and thermal stability. This study presents a novel garnet-type blue phosphor, Ca 3 Gd 2 Si 3 O 12 :Ce 3+ , synthesized via solid-state reaction. Under 356 nm excitation, it emits intense blue light (peak at 411 nm) with a broad FWHM of 80.91 nm, outperforming commercial phosphors like BaMgAl 10 O 17 :Eu 2+ . Its emission closely matches chlorophyll absorption, achieving overlap efficiencies of 84.14 % (chlorophyll a ) and 94.81 % (chlorophyll b ). The phosphor also exhibits excellent thermal stability (activation energy: 0.296 eV; T 50 = 387 K). Additionally, when integrated into WLEDs with red/green phosphors, Ca 3 Gd 2 Si 3 O 12 :Ce 3+ delivers warm white light (CCT = 4512 K, CRI = 92.3), demonstrating versatility in both plant growth and high-quality lighting applications. LEDs with this study's blue phosphor have higher CRI than ordinary lighting LEDs (reducing blue light harm) and a broad spectrum, better suiting plant growth compared to traditional blue plant LEDs.
研究领域:
材料科学
·
光电子学
·
植物生物学
·
固态照明
·
应用物理学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Qingyun He,Yaqian Zhang,Yanxia Yu,Ya Chen,Mengfeifei Jin,Enrou Mei,Xiaojuan Liang,Lanlan Zhai,Weidong Xiang
Here, Gd-doped CsPbBrI 2 nanocrystals (NCs) in borosilicate glass (B 2 O 3 -SiO 2 -ZnO) were successfully synthesized by the traditional melting quenching method. The optical properties of CsPbBrI 2 NCs@glasses at different heat treatment temperatures and the content of Gd 3+ were studied. It is found that CsPbBrI 2 NCs@glasses have greatly improved photoluminescence quantum yields (PLQYs) after doping (form 15.3% to 37%) and excellent hydrothermal and light stability. In addition, a white light emitting diode (WLED) was successfully prepared by combining Gd-doped CsPbBrI 2 NCs@glass and Ce 3+ : YAG phosphors with the blue light emitting diode (LED). After a series of adjustments, the high performance WLED device with a chromaticity coordinate (CIE) of (0.3340, 0.3386), luminous efficiency (LE) of 90.09 lm/W, correlated color temperature (CCT) of 5430 K and the color rendering index (CRI) of 81.4 was fabricated. This work provides a new strategy in the field of metal ion doped perovskite NCs for future reference and has potential applications in LEDs.
研究领域:
材料科学
·
光学工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
EcoMat
·
2022
·Vol. 4
·期 2
·e12184
·
IF 12.213
Baiqian Wang,Chen Chen,Xin Yang,Wensi Cai,Shuangyi Zhao,Ru Li,Wen Ma,Jiangzhao Chen,Zhigang Zang
Owing to the excellent optical properties, white light-emitting diodes (WLEDs) based on metal halide perovskites have attracted great attention as promising light source for solid-state lighting and wireless visible light communication (VLC). However, the instability and toxicity of classic hybrid lead halides hinder their practical applications. Here, a pressure-assisted cooling method is developed to grow lead-free Cs 3 Cu 2 I 5 and CsCu 2 I 3 single crystals, which exhibit more excellent stability, larger size and uniform orientations in comparison with pressure-free cooling method. Then, both single crystals are used as the emitters of WLEDs without encapsulation, exhibiting a high Color Rendering Index of 91, a decent Commission Internationale de l'Eclairage coordinate of (0.33, 0.33), a proper Correlated Color Temperature of 5436 K, as well as an excellent 1350-h operating stability at atmosphere. Furthermore, the prepared WLEDs are utilized in wireless VLC, which possesses a −3 dB bandwidth of 10.1 MHz.
研究领域:
材料科学
·
光电
·
固态照明
·
可见光通信
✓ 已验证
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 9
·4850-4856
·
IF 2.936
Qian Liu,Danting Li,Zhifeng Zhu,Shimeng Yu,Yan Zhang,Dabin Yu,Yang Jiang
To achieve competitive fluorescence carbon dots (CDs), studies on regulating fluorescence of CDs under controlled, comparable conditions are in great demand. Herein, by changing the functional groups and nitrogenous existence forms in the precursors, three efficient yellow-green emissive N-doped CDs which have the same fluorescence peak wavelength but different photoluminescence quantum yields were realized through a facile hydrothermal method. The as-prepared CDs exhibit not only excited-independent emissions but also similar surface states. The best-performing CDs among the three products exhibits photoluminescence quantum yields of up to 24.4% in water and 53.3% in ethanol, abundant surface functional groups and its high N-doping degree would be the reason for its excellent performances. By washing and reduction processes, the emission evolution of the CDs was studied linking the changes of surface states. The fluorescence can certainly be attributed to the surface of the carbon dots, and the surface states control the photoluminescence features. Serving as a yellow-green colour conversion layer, the best CDs in the three products was used to fabricate a white light-emitting diode. The white light-emitting diode shows an excellent colour rendering index up to 93.3, suggesting broad application prospects of the CDs in lighting and display fields.
研究领域:
材料科学
·
光学
·
能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF RARE EARTHS
·
2023
·
IF 4.9
Wei Zhang,Changjian Wang,Xusheng Qiao,Xianping Fan
The rapid development of phosphor-converted white light emitting diodes (pc-WLEDs) requires new red phosphors with efficient and thermally stable luminescence for high-quality warm-white lighting. However, it is still a challenge to discover red phosphors with facile synthesis, high internal quantum efficiency (IQE), excellent thermal stability and high color purity. Herein, a novel red-emitting Eu 3+ activated barium dialuminum digermanate (BaAl 2 Ge 2 O 8 , BAGO) phosphor showing strong red emission at 610 nm was prepared. The IQE is improved from 32.91% to 78.84% by employing a charge compensation strategy. The lithium-ion co-doped BAGO:Eu 3+ phosphor exhibits a nearly twofold increase in integral photoluminescence (PL) intensity and the high color purity reaches 94.17%. Impressively, the PL intensity of the BAGO:Eu 3+ ,Li + phosphor drops by only 2.6% at 150 °C of that at room temperature. Finally, the pc-WLED using the red BAGO:Eu 3+ ,Li + phosphor exhibits white light with the chromaticity coordinate of (0.3515, 0.3495), a high color-rendering index of 92 and a low correlated color temperature of 4746 K. All these results manifest that BAGO:Eu 3+ ,Li + phosphor is a suitable red phosphor for near-ultraviolet (NUV) chip-based pc-WLEDs.
研究领域:
材料科学
·
光电
·
发光二极管
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）