Journal of Materials Chemistry C
·
2025
·Vol. 13
·期 20
·10390-10398
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IF 5.1
Yi Xu,Xuewan Lin,Jiyou Zhong
Near-infrared phosphor-converted light-emitting diodes (NIR pc-LEDs) have emerged as ideal light sources for a variety of advanced spectroscopy applications, demonstrating the importance of developing efficient NIR phosphors. In this work, a Ti4+-containing garnet, Na2CaTi2Ge3O12, was selected as the host material to minimize the ionic size mismatch after Cr3+ substitution. Interestingly, this substitution generates charge self-balance, enabling excellent efficiency of the developed material. Under 465 nm excitation, it exhibits broadband emission covering the first NIR window (λem,max = 790 nm) with a full width at half maximum (FWHM) of 120 nm. The optimized sample achieved a photoluminescence quantum yield (PLQY) of 75%. Moreover, a NIR pc-LED device was fabricated by combining the optimized phosphor with a blue (λem = 455 nm) InGaN chip. Upon application of a driving current of 100 mA, the device demonstrated a NIR output power of 18.24 mW and a corresponding NIR photoelectronic conversion efficiency of 6.49% and exhibited excellent performance in biological tissue imaging and non-destructive testing. Therefore, this work provides an efficient NIR phosphor, which has promising potential in spectroscopy applications.
研究领域:
材料科学
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光学
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生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2024
·Vol. 26
·期 24
·17182-17190
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IF 2.9
Zhe-Yong Chen,Xue Ren,Hui-Ling Hu,Meng Liu,Yi Liu,Feng-Lei Jiang
ZnSeTe quantum dots (QDs) attract growing interest owing to their low threats to health and the environment. They are widely applied as emitters in displays and lighting devices. Previous findings have indicated that inorganic halides are excellent candidates for surface ligands on QDs. By incorporating inorganic halides during the synthesis process, the photoluminescence (PL) intensity and quantum yield (QY) of QDs can be significantly enhanced. However, the alteration of surface states in QDs induced by zinc halide modification and the mechanism of formation of trap-state radiative recombination processes have been less discussed. Herein, we proposed a synthesis strategy for ZnSeTe/ZnSe/ZnSeS/ZnS core/shell/shell/shell QDs modified with ZnCl2, and by comparing the morphology and elemental composition of QDs with different amounts of ZnCl2 added, we revealed the regulatory mechanism of nanocrystal growth in the presence of ZnCl2. QDs with modification of ZnCl2 exhibited broad yellow fluorescence, distinct from the intrinsic blue emission. Through spectroscopic and surface ligand analyses, we attributed this yellow emission to the intermediate state energy levels caused by the defects on the surface. Finally, we used the QDs with broad linewidth emission to fabricate a simple white-light-emitting diode (WLED). This work provided new insights into the role of inorganic ligands and the use of a single emitting material in solid-state lighting devices.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2023
·Vol. 33
·期 25
·2300583
·
IF 19
Min Peng,Shibin Sun,Bin Xu,Zhengtao Deng
Currently, the most popular way to manufacture white light-emitting diodes (WLEDs) is based on blue-emitting InGaN LED chips (440–460 nm) and yellow-emitting phosphor coating (520–700 nm) to produce white light lighting. However, because conventional white WLEDs lack the uniformly distributed continuous emission spectrum compared to natural sunlight: “blue overshoot” (extra 440–460 nm blue-light can cause damage to the retina) and “cyan gap” (470–520 nm wavelength range). Here, a novel strategy to “kill two birds with one stone” is reported: using the stable and bright polymer encapsulated perovskite nanocrystals (PNCs) composite films as the cyan color converters that efficiently absorb the “blue overshoot” and effectively emit the cyan light to fill the “cyan gap”. A series of polymer-encapsulated PNC films is achieved that can reach very high photoluminescence quantum yield (PL QY) of 90–95% under 450 nm blue-light excitation. Importantly, both 370 nm UV-excited WLED and 455 nm blue-excited WLED devices are constructed that exhibit smoothly and evenly distributed white light without blue overshoot and cyan gap, which was not achieved before for blue-excited cyan-emissive materials. This study paves the way toward the application of PNC color converters in the next generation full-visible-spectrum WLED lighting that mimic the natural daylight.
研究领域:
材料科学
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光学工程
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纳米技术
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DOI
高影响因子
Nano-Micro Letters
·
2023
·Vol. 16
·期 1
·1-13
·
IF 26.6
Xiao Guang,Li Hao,Yu Zhizhou,Niu Haoting,Yao Yagang
Highly thermally conductive composite films with elimination of graphene nanosheet wrinkles prepared by a constrained drying strategy of in-plane stretching.
Reveals the mechanism of graphene nanosheet wrinkle elimination to improve the thermal conductivity of composite films and demonstrates its use as a heat sink film for cooling flexible LED chips and smartphones.
研究领域:
材料科学
·
热管理技术
·
纳米科技
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2020
·
IF 3.28
Shijie Qiu,Hengwei Wei,Xiaoming Wang,Shuai Zhang,Mengmeng Wang,Yiying Wang,Ling Xu,Huan Jiao
A series of efficient red phosphors, K 2 SiF 6 :Mn 4+ (KSFM) particles with highly regular, uniform and anisotropic shapes, were successfully prepared by a two-step chemical co-precipitation method at room temperature without using surfactant and template. A morphological map for KSFM particles with five distinctive shapes was depicted by adjusting KF-HF precipitator dropping speed. Moreover, the photoluminescence , decay curves and Raman spectral dependence of the KSFM phosphors with different morphologies were investigated. Luminescence intensity of the KSFM phosphors is highly correlated with the morphology of KSFM particles, which gradually increased as the particle shapes changed from cube to octahedron . Whereas, Raman spectra and flame atomic absorption spectrophotometer results indicated that Mn 4+ concentration in a series of KSFM particles decreased gradually. Growth mechanism of particle is discussed base on reticular density and surface energy. White LED devices made of a blue GaN chip merged with yellow phosphor (YAG: Ce 3+ ) and the obtained KSFM red phosphor could produce warm white light. Drive current testing of the fabricated w-LEDs proved the KSFM phosphor in octahedron shape is more stable than that of the KSFM in cubic shape.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Xiaoqian Dong,Zhibin Chen,Lehui Liu,Feifei Yuan,Yisheng Huang,Lizhen Zhang,Zhoubin Lin
Broadband near-infrared (NIR) phosphors play a crucial role in the development of next-generation smart NIR light sources based on blue light-emitting diodes (LEDs). The emission bandwidth is an important parameter for evaluating the performance of these phosphors. Herein, an ultra-broadband NIR phosphor CaMgSi 2 O 6 :Cr 3+ (CMSO:Cr), with a tunable emission band and a full width at half maximum (FWHM) ranging from 138 nm to 393 nm, is obtained by adjusting the doping concentration of Cr 3+ . In the low-concentration doped sample, a single emission peak at 785 nm is observed. When the concentration of Cr 3+ exceeds 1.0 at%, emissions at both 785 nm and 980 nm are detected. The emission peak at 785 nm originates from the [MgO 6 ](Ⅰ) octahedron within the CMSO structure. On the other hand, the emission peak at 980 nm is attributed to the presence of a twisted octahedron [MgO 6 ](Ⅱ), which is caused by defects and vacancies resulting from the charge imbalance when Mg 2+ ions are replaced by Cr 3+ ions. The Cr 3+ ion primarily occupies the [MgO6](Ⅰ) site in the lower-concentration doped sample, which explains the photoluminescence peak at 785 nm. With the increase in the concentration of Cr 3+ ions, more and more Cr 3+ ions preferentially occupy the [MgO 6 ](Ⅱ) octahedral sites, leading to the broad emission at 980 nm. A novel NIR phosphor light source was fabricated by combining a blue chip with CMSO:Cr phosphor. Driven by a current of 60 mA, the NIR light output power of 5.89 mW and 0.76 mW is achieved by using CMSO:0.015Cr and CMSO:0.04Cr, respectively. This work demonstrates that new luminescent centers can be generated by substituting heterovalent ions, resulting in broadened emission spectra.
研究领域:
材料科学
·
光电
·
光子学
✓ 已验证
DOI
高影响因子
Advanced Optical Materials
·
2023
·Vol. 12
·期 11
·2302380
·
IF 9
Xiangyi Dai,Xikun Zou,Haoran Zhang,Weibin Chen,Chaowei Yang,Maxim S. Molokeev,Zhiguo Xia,Yingliang Liu,Xuejie Zhang,Mingtao Zheng,Bingfu Lei
Cr 3+ -doped phosphors are highly recognized in various fields for their remarkable luminous efficiency and spectral flexibility, including modern agriculture and horticulture. However, the shortage of suitable Cr 3+ -doped phosphors for far-red LED devices has inhibited their popularization in plant lighting. Herein, an innovative Cr 3+ -doped phosphor Ca 2 YAl 3 Ge 2 O 12 :Cr 3+ (CYAG:Cr 3+ ), achieving a broad far-red emission at 770 nm upon 450 nm blue light excitation is designed. The optimal CYAG:Cr 3+ phosphor exhibits a high internal quantum yield of 78.2% and low thermal-quenching behavior of 85%@373 K. Thus, the fabricated phosphor-converted LEDs (pc-LEDs) for plant far-red lighting have a high output power of 33.3 mW and photovoltaic conversion efficiency of 11.5% at 100 mA. The potential of CYAG:Cr 3+ in plant lighting is assessed by supplementing the far-red lighting of Italian lettuce with fabricated pc-LEDs, and the biomass of Italian lettuce is significantly increased by 33%. The successful development of CYAG:Cr 3+ phosphors provides a high-quality option for plant far-red light devices and further stimulates the development of new Cr 3+ -doped plant-lighting phosphors.
研究领域:
材料科学
·
农业与植物学
✓ 已验证
DOI
高影响因子
Advanced Optical Materials
·
2024
·
IF 8
Chaowei Yang,Dongwei Zheng,Xikun Zou,Xiangyi Dai,Baoling Tang,Maxim S. Molokeev,Xuejie Zhang,Haoran Zhang,Yingliang Liu,Bingfu Lei
Far-red (FR) region (beyond 700 nm) lighting sources possess special potential for plant lighting. However, it remains a challenge to obtain high-performance Cr 3+ -doped FR phosphors. This study developed a FR phosphor, Ca 1.8 Mg 1.2 Al 2 Ge 3 O 12 :Cr 3+ (CMAGG: Cr 3+ ), using the cation substitution strategy. Under 438 nm blue light excitation, the phosphors display FR emission centered at 720 nm with a full width at half maximum (FWHM) of 91 nm. Benefit from the favorable match with the FR phytochrome (P fr ), the phosphor is combined with InGaN blue light chips to create a FR phosphor-converted light-emitting diode (pc-LED), which is used in Italian lettuce growth experiments and it results shown in a 15% increase in fresh weight and a 6.5% increase in dry weight. Notably, supplemental FR light modulated its growth morphology. The results of this study will be useful for further research on novel Cr 3+ -doped FR phosphors to meet the precise spectral requirements for plant growth.
研究领域:
植物学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2020
·
IF 3.28
Wei Yan,Xiaohan Yun,Hang Yang,Yi Wei,Guogang Li
Nowadays, non-rare-earth Mn 4+ -activated red phosphors have emerged for improvement of the lighting quality of phosphor-converted white light-emitting-diodes (pc-WLED), owing to the low cost and the admirable luminescence properties. In this work, a novel narrow-band red-emitting Li 3 CsGe 8 O 18 :Mn 4+ phosphor was synthetized based on the component substitution from Li 3 RbGe 8 O 18 , which exhibits the red luminescence centered at 668 nm upon 466 nm excitation. By further designing [Cs + -Rb + ] cation substitution, the photoluminescence intensity and luminescence efficiency are obviously improved. The photoluminescence intensity enhanced 1.75 times than Li 3 RbGe 8 O 18 :Mn 4+ phosphor, while the corresponding internal quantum efficiency (IQE) increased by 1.57 times. According to the Rietveld refinement results, the corresponding mechanism of luminescence enhancement is attributed to the smaller distortion degree of the [Ge(1)O 6 ] octahedron . The pc-WLED device is fabricated by the optimal Li 3 Cs 0.5 Rb 0.5 Ge 8 O 18 :1%Mn 4+ red phosphor, yellow phosphor with Y 3 Al 5 O 12 :Ce 3+ and 460 nm InGaN chip, showing a warm white light emission with low correlated color temperature (4474K) and high color rendering index (90.8). The result implies that the Li 3 Cs 0.5 Rb 0.5 Ge 8 O 18 :1%Mn 4+ phosphor can be used as a potential red phosphor for pc-WLED application.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
Materials Chemistry Frontiers
·
2019
·Vol. 3
·期 10
·2120-2127
·
IF 0
Qiang Zhang,Xicheng Wang,Zuobin Tang,Yuhua Wang
A novel blue-emitting phosphor, Na3ScSi2O7:Ce3+ (NSSO:Ce3+), was synthesized with a solid-state method at low temperature successfully. Its crystal structure, band structure, and photoluminescence and cathodoluminescence properties were researched in detail. The phase formation and the crystal structure were confirmed by powder X-ray diffraction analysis and the Rietveld refinement method, respectively. Under the excitation of n-UV light, the optimal NSSO:0.02Ce3+ phosphor can yield blue emission centered at 452 nm with a high quantum efficiency of 50.9%. The PL intensity of the NSSO:0.02Ce3+ phosphor remains at 71.46% of the initial value when the temperature is increased from room temperature to 150 °C, indicating good thermal stability. A WLED lamp was obtained by combining a 360 nm n-UV chip with Sr2SiO4:Eu2+, (Ca, Sr)AlSiN3:Eu2+ and NSSO:0.02Ce3+ phosphors, in which the color coordinates, CCT and CRI are (0.360, 0.348), 4409 K and 90.9, respectively. Moreover, under low voltage electron bombardment, the phosphor can emit blue emission with high luminescence intensity, current saturation and resistance. All the results indicate that the NSSO:Ce3+ phosphor shows much potential for the application of both WLEDs and field emission displays (FEDs). Our research has also offered a new insight and perspective that using Sc-based sorosilicates as host can be an appropriate strategy for developing excellent inorganic luminescence materials.
研究领域:
材料科学
·
光学工程
·
无机化学
·
固态照明
·
显示技术
✓ 已验证
DOI
OPTICAL MATERIALS
·
2025
·
IF 4.2
Liang Dong,Ziying Wang,Sihan Yang,Qi Zhu,Ji-Guang Li,Xuejiao Wang
Phosphor-converted white light-emitting diode (pc-WLED) is crucial for solid-state lighting, but the color rendering index of commercial pc-WLED needs to be improved. In this study, a series of silicates KSrScSi 2 O 7 : x Ce 3+ ( x= 0-10at%) were synthesized. Under the 365 nm near-ultraviolet excitation, the silicate emits a high-quality broadband cyan-blue light (385-550 nm) covering the cyan gap. The emission intensity reaches its maximum at approximately 450 nm and the emission peak is slightly shifted with varying Ce 3+ concentration, which is because Ce 3+ doping changes the crystal field around the luminescence center. The prepared phosphors showed promising properties for application in high-color rendering lighting. The crystal structure analysis via X-ray diffraction and Rietveld refinement and Gaussian fitting of the PL spectra indicated that Ce 3+ occupies the Sr 2+ and K + positions in the monoclinic host lattice. The optimal Ce 3+ content is 3at% and concentration quenching is attributed to the non-radiative energy transfer between the nearest-neighboring Ce 3+ ions. The temperature-dependent luminescence showed that the T 50 is 394 K for the KSrScSi 2 O 7 : x Ce 3+ materials. The thermal quenching is attributed to increased lattice vibrations and enhanced non-radiative transitions at elevated temperatures. The performance of the pc-WLED device fabricated with KSrScSi 2 O 7 : 3at%Ce 3+ was studied, and the device showed a high-color rendering index (Ra=93.8) and exceptional stability during operation.
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
JOURNAL OF LUMINESCENCE
·
2024
·
IF 3.3
Changlin Li,Siyu Cheng,Yilian Ran,Xiya Miao,Dongze Li,Yangyu Su,Yuchen Yang,Xianchao Du,Xiang Liu,Ruijin Yu
The novel orange-red emitting K 5 Y(MoO 4 ) 4 : x Sm 3+ (KYMO: x Sm 3+ ) (1 mol% ≤ x ≤ 35 mol%) phosphors were synthesized through solid-phase reaction. The KYMO:Sm 3+ phosphors were mainly analyzed for purity phase, luminescence properties, and thermostability. Under 403 nm excitation, KYMO:10 mol%Sm 3+ possesses four distinct emission peaks. The dominant emission peak is situated at 645 nm, corresponding to the 4 G 5/2 → 6 H 7/2 electron transitions. With x = 10 mol%, the KYMO: x Sm 3+ phosphor has the optimal doping concentration. The color purity reaches as high as 99.9 %. KYMO:10 mol%Sm 3+ presents good thermostability with T 0.5 > 480 K and resistance to color drift (Δ E = 0.012 at 420 K). The lifetime for KYMO:10 mol%Sm 3+ is 1.16 ms. The internal quantum efficiency (IQE) reaches 62.74 %. At 480 K, the maximum temperature sensing sensitivities of the FIR of I 564 /I 599 are 5.19 × 10 −4 ( S a ) and 18 % ( S r ). The assembled WLED displays an excellent color rendering index (CRI, R a ) of 94, Commission International de L′ Eclairage (CIE) coordinates (0.333, 0.346), and a correlated color temperature (CCT) of 5464 K. In summary, KYMO:Sm 3+ phosphors possess great promise for high CRI white-light-emitting diodes (WLEDs) and potential feasibility for temperature sensing.
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
危险品化学品经营许可证（带存储）