Nanoscale Research Letters
·
2018
·Vol. 13
·期 1
·1-7
·
IF 3.125
Zhang Guilin,Mei Shiliang,Wei Xian,Wei Chang,Yang Wu,Zhu Jiatao,Zhang Wanglu,Guo Ruiqian
In this letter, dual-emissive and color-tunable Mn-doped InP/ZnS quantum dots (Mn:InP/ZnS QDs) with the absolute photoluminescence quantum yield (PL QY) up to 78% were successfully synthesized via a growth-doping method. The dual emission of Mn:InP/ZnS QDs is composed of intrinsic emission and Mn-doped emission, which can be tuned by different Mn/In ratios. With the increase of Mn dopant concentration, the intrinsic emission shows a red shift from 485 to 524 nm. The new class of dual-emissive QDs provides potential for future application in white LED.
研究领域:
材料科学
·
纳米技术
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产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2018
·Vol. 6
·期 46
·12631-12637
·
IF 5.976
Kang Yuan,Xinghua Zhang,Ruohan Qin,Xuefeng Ji,Yahui Cheng,Lanlan Li,Xiaojing Yang,Zunming Lu,Hui Liu
Controlling surface states using different functional groups is an effective and facile way to modulate the fluorescence of carbon dots (CDs), but the underlying mechanisms are still unclear and urgent to solve. In this work, we synthesized red emitting CDs and achieved multiple emission states (red, green and blue emission) by tailoring the surface states with different amino groups. In particular, the luminescence mechanism and the role of surface states were studied in detail. It is found that the multiple emission states are related to the speciation of nitrogen (pyridinic N, pyrrolic N, graphitic N and amino N) on the surface of CDs, of which the fluorophore formed by the deformation of p-phenylenediamine contributes to the red emission, pyridinic N is responsible for the green emission state, and pyrrolic N enhances the blue emission. A possible energy level diagram was proposed to disclose the electron transition process and relative levels induced by different surface groups on CDs. In addition, the modulated CDs with multiple emission states can be used as single light converters to fabricate a white light-emitting diode, which has white light color coordinates of (0.31, 0.32), a high color rendering index (CRI) of 85, a luminous efficiency of 8.8 lm W−1 and good stability.
研究领域:
材料科学
·
光学工程
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2015
·
IF 2.999
Renping Cao,Yunling Cao,Ting Fu,Shenhua Jiang,Wensheng Li,Zhiyang Luo,Jingwei Fu
Novel red phosphors R 3 P 4 O 13 :Bi 2+ (R = Sr and Ba) are synthesized by solid state reaction method in air, and their crystal structures and fluorescence properties are characterized. The excitation bands peaking at ∼440 nm match with the blue LED chip, and their red emission band peaking at ∼658 and 686 nm within the range 580–800 nm owing to 2 P 3/2 (1) → 2 P 1/2 the transition of Bi 2+ ions can be observed, respectively. The relation between Bi 2+ doping concentration and emission intensity is discussed and the optimal Bi 2+ ion doping concentration is ∼3.0 mol%. Decay curves and time-resolved spectra confirm that R 3 P 4 O 13 :Bi 2+ (R = Sr and Ba) phosphors have only single Bi 2+ center. The luminous mechanism is explained by energy level diagram of Bi 2+ . The luminescence properties indicate that R 3 P 4 O 13 :Bi 2+ (R = Sr and Ba) phosphors have a potential to be used as red emitting phosphor candidate for white LEDs based on ∼440 nm blue LED chip.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2022
·
IF 3.754
Yun Tang,Ben Liu,Nan Yan,Xiaoqiang He,Hudie Yuan,Yalou Xin,Hongfeng Yin
Widespread application of YAG:Ce-based white light-emitting diodes (WLEDs) is being challenged due to the lack of red emission, leading to their poor color rendering index (Ra) and high correlated color temperature (CCT). Perovskite quantum dots (QDs), presenting high photoluminescence quantum yield and simple fabrication process have been recognized as promising red-emitting component for warm WLEDs. However, conventional method by mechanically mixing QDs with YAG:Ce always results in undesirable dispersion due to their huge size difference. Moreover, the two components display different sinking behavior in silicone , which would further deteriorate the color uniformity of WLED. To address these issues, in this study, red-emitting MAPbBr 3-x I x QDs-coated YAG:Ce (A-YAG@QDs) composites were successfully prepared to further fabricate WLED with compensated red emission. The chemical coordination interactions between QDs and functionalized YAG:Ce make the two components behave as a whole, which effectively avoids the dispersion and sinking-related issues. The WLED, which combined blue LED chip and A-YAG@QDs composite, exhibited warm white light with low CCT of 4474 K, high Ra of 90.1 and high value of saturated red color component R9 as 95. This study demonstrated a promising strategy to prepare QDs-coated phosphor composites for the generation of warm white light for indoor lighting application.
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
Materials Today Communications
·
2023
·
IF 3.8
Hongyu Chen,Yunfei Wang,Jianing Wang,Yajuan Wang,Wenyan Liu
In recent years, CuInS 2 quantum dots have shown great potential for various applications due to their wide excitation wavelength range, symmetric emission wavelength range, long fluorescence lifetime and optical stability. However, the high cost of indium (In) limits its commercialization. In this study, we partially substituted the expensive In element with more affordable and abundant aluminum (Al) to reduce the cost of CuInS 2 quantum dots. CuInS 2 , CuAlInS, CuInS 2 /ZnS and CuAlInS/ZnS core/shell quantum dots were synthesized using one-pot method. Due to the incorporation of Al, their photoluminescence (PL) spectra exhibit a blue shift of about 5 nm. A time-resolved PL measurement indicated that the PL lifetime of the quantum dots was a characteristic feature of three dominating transitions from the conduction band to surface defect level, from the conduction band to an acceptor level, and from the donor level to an acceptor level. The temperature-dependent PL proves that after the introduction of Al, the FWHM of quantum dots does not show significant broadening with increasing temperature. Finally, CuInS 2 /ZnS and CuAlInS/ZnS quantum dot phosphor LEDs are produced. The brightness of the CuAlInS/ZnS quantum dot phosphor LED is slightly higher than that of CuInS 2 /ZnS quantum dot phosphor LEDs. The red-emitting CuAlInS/ZnS quantum dot phosphor LED with easy fabrication and no need for encapsulation can compensate for the lack of red light in warm white LED applications in future research.
研究领域:
材料科学
·
半导体物理
·
光电
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NON-CRYSTALLINE SOLIDS
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2023
·
IF 3.5
Jiachen Chen,Jin Li,Beining Li,Zhuocheng Chen,Xue Bai,Long Zhang,Jin He
The development of advanced luminescent materials is highly desirable for developing the energy-efficient lighting technology. However, it is still challenging to achieve stable full-color tuning in the same matrix upon a single-beam light excitation so as to ensure the high color stability and consistency. Herein, Eu 3+ /Eu 2+ /Tb 3+ co-doped sintered nanoporous glass via the dipping strategy is fabricated, which can emit blue, green and red emissions simultaneously by simply modifying the thermal treatment temperature. This full-color tuning is attributed to the dual roles of the thermal reduction of Eu 3+ to Eu 2+ in Al 2 O 3 -SiO 2 glass and simultaneous emissions of Eu 3+ /Eu 2+ /Tb 3+ activators. The densification of nanoporous glass via sintering could effectively decrease the amount of hydroxyl groups that present in the glass matrix, resulting in 5 times enhancement of the photoluminescence intensity and longer photoluminescence lifetime of rare earth (RE) ions. The thermal reduction of Eu 3+ to Eu 2+ is due to the reduction environment provided by Al 3+ ions in the Al 2 O 3 -SiO 2 glass. The energy transfer (ET) from Eu 2+ to Tb 3+ , Eu 2+ to Eu 3+ and Tb 3+ to Eu 3+ have been investigated in detail. Based on the ET mechanism, rational PL spectra design was demonstrated by varying the concentration of Eu 3+ ions in solution. The Color Correlated Temperature (CCT) and the Color Rendered Index (CRI) values of the white light emission glass are 7420 K (Cold-white emission) and 80.85, the temperature dependent photoluminescence (TDPL) analysis reflects the white light emission glass possesses high thermal stability and excellent thermal restorability. This facile fabrication and full-color tuning of Eu 3+ /Eu 2+ /Tb 3+ co-doped sintered nanoporous Al 2 O 3 -SiO 2 glass may provide a novel luminescent material for white-light emitting diodes (WLEDs) application.
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
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Shuaiqi Zhao,Xiaolei Yang,Yumeng Ge,Hongbin Zhang,Jie Li,Keyu Han,Shiqing Xu,Gongxun Bai
The all-inorganic perovskite nanocrystals are promising luminescent materials for optoelectronic devices. However, it is still a challenge to prepare perovskite nanocrystals with high luminescence. Herein, a synthesis method was developed for the uniform incorporation of ultra-thin BiOBr nanosheets into perovskite crystals at both body-embedding and surface-passivating positions. The micron-scale green-emitting phosphors composed of Cs 4 PbBr 6 nanocrystals and BiOBr nanosheets are prepared. The crystal structure of Cs 4 PbBr 6 nanocrystals can remain almost unchanged although prepared from different PbBr 2 concentrations. The luminescence mechanism of Cs 4 PbBr 6 is discussed. The Cs 4 PbBr 6 @BiOBr submicron phosphors can be dispersed in DMSO solvent without disintegration and dissolution, which are used as seeds of the CsPbBr 3 film growth. The CsPbBr 3 films with Cs 4 PbBr 6 @BiOBr doped exhibit pure optical characteristics of CsPbBr 3 , indicating that Cs 4 PbBr 6 is converted to CsPbBr 3 during the film preparation process. Furthermore, these Cs 4 PbBr 6 @BiOBr phosphors are mixed with CaAlSiN 3 : Eu red-emitting commercial phosphors to make white LEDs (WLEDs). Overall, this study provides a revealing insight into a kind of composite material constructed with halide perovskite and bismuth halide oxide.
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
PHYSICA B-CONDENSED MATTER
·
2023
·
IF 2.8
Wang Bo-Hao,Dan Zhao,Zhang Rui-Juan,Yao Qing-Xia,Jia Lei
Developing new phosphors is an important issue for white LED applications. Herein, a simple compound NaAlO 2 with an unusual compact 5-coordinated [NaO 5 ] polyhedral environment is selected as host material. After doping Bi 3+ into NaAlO 2 , Bi 3+ may be occupy the Na-sites and interesting luminescent properties are expected. Experimental results show that phosphor NaAlO 2 :Bi 3+ can emit cyan light under near-UV excitation. More exciting, the luminescent intensity of NaAlO 2 is rather stable under high temperatures, which is due to the good structural rigidity of NaAlO 2 host lattice and the process of trap-to-activator energy transfer. At 450 K, the typical working condition of LED devices, the PL intensity constitutes 92 % of the intensity at 300 K, which can guarantee its luminous efficiency for applications in LED devices. Finally, a white LED was fabricated by using a 365 nm LED ship, and a mixture of CaAlSiN 3 :Eu 2+ (red phosphor), BaMgAl 10 O 17 :Eu 2+ (blue phosphor) and NaAlO 2 :0.007Bi 3+ . The CIE coordinates, rendering index (Ra) and Correlated Color Temperature (CCT) of this lamp are (0.3183, 0.3307), 96.8 and 4429 K. This work confirms that the NaAlO 2 :Bi 3+ material is a promising cyan phosphor for applications in LED field.
研究领域:
材料科学
·
光学工程
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产品关联
DOI
高影响因子
PROTEIN SCIENCE
·
2020
·Vol. 30
·期 3
·558-570
·
IF 3.876
Shuhao Li,Yang Zou,Dongping Zhao,Yuqing Yin,Jingyi Song,Ningning He,Huadong Liu,Dongmeng Qian,Lei Li,Haiming Huang
Protein engineering through directed evolution is an effective way to obtain proteins with novel functions with the potential applications as tools for diagnosis or therapeutics. Many natural proteins have undergone directed evolution in vitro in the test tubes in the laboratories worldwide, resulting in the numerous protein variants with novel or enhanced functions. we constructed here an SH2 variant library by randomizing 8 variable residues in its phosphotyrosine (pTyr) binding pocket. Selection of this library by a pTyr peptide led to the identification of SH2 variants with enhanced affinities measured by EC50. Fluorescent polarization was then applied to quantify the binding affinities of the newly identified SH2 variants. As a result, three SH2 variants, named V3, V13 and V24, have comparable binding affinities with the previously identified SH2 triple-mutant superbinder. Biolayer Interferometry assay was employed to disclose the kinetics of the binding of these SH2 superbinders to the phosphotyrosine peptide. The results indicated that all the SH2 superbinders have two-orders increase of the dissociation rate when binding the pTyr peptide while there was no significant change in their associate rates. Intriguingly, though binding the pTyr peptide with comparable affinity with other SH2 superbinders, the V3 does not bind to the sTyr peptide. However, variant V13 and V24 have cross-reactivity with both pTyr and sTyr peptides. The newly identified superbinders could be utilized as tools for the identification of pTyr-containing proteins from tissues under different physiological or pathophysiological conditions and may have the potential in the therapeutics.
研究领域:
分子生物学
·
蛋白质工程
·
生物化学
✓ 已验证
DOI
PubMed
高影响因子
ACTA PHARMACOLOGICA SINICA
·
2021
·Vol. 43
·期 8
·2139-2146
·
IF 6.15
Huang Dong,Zhao Ying-yuan,Wang Rui-min,Li Wei,Yuan Fang-yu,Yan Xue-long,Yang Xiao,Tang Gui-hua,Yin Sheng,Bi Hui-chang
Cholestasis is a major cause of a series of bile flow malfunction-related liver diseases. Pregnane X receptor (PXR) is a key regulator in endo- and xeno-biotics metabolism, which has been considered as a promising therapeutic target for cholestasis. In this study we conducted human PXR (hPXR) agonistic screening using dual-luciferase reporter gene assays, which led to discovering a series of potent hPXR agonists from a small Euphorbiaceae diterpenoid library, containing 35 structurally diverse diterpenoids with eight different skeleton types. The most active compound 6 , a lathyrane diterpenoid (5/11/3 ring system), dose-dependently activated hPXR with a high selectivity, and significantly upregulated the expression of hPXR downstream genes CYP3A4 and UGT1A1 . In LCA-induced cholestasis mouse model, administration of compound 6 (50 mg· kg −1 . d −1 , ip) for 7 days significantly suppressed liver necrosis and decreased serum levels of AST, ALT, Tbili, ALP, and TBA, ameliorating LCA-induced cholestatic liver injury. We further revealed that compound 6 exerted its anti-cholestatic efficacy via activation of PXR pathway, accelerating the detoxification of toxic BAs and promoting liver regeneration. These results suggest that lathyrane diterpenoids may serve as a promising scaffold for future development of anti-cholestasis drugs.
研究领域:
药理学
·
肝病学
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Zhiyuan Pan,Sihan Feng,Fan Li,Xuejiao Wang,Qi Zhu,Ji-Guang Li
Near-infrared phosphor converted light-emitting diodes (NIR pc-LEDs), as a state-of-the-art type of NIR sources, are finding multifaceted applications, where phosphor is a crucial component. In hope to provide new choices for NIR lighting, we synthesized in this work the two series of Ruddlesden -Popper type layered perovskite phosphors of SrLa 2 Al 2- x O 7 : x Cr 3+ ( x = 0–0.02) and SrLa 2- y Gd y Al 1.984 O 7 :0.016Cr 3+ ( y = 0–2), followed by detailed structure and luminescence investigation. SrLa 2 Al 2- x O 7 : x Cr 3+ was found to emit ∼700–800 nm NIR light under UV excitation and be able to maintain ∼54.3 % of its room temperature intensity at 423 K, which is remarkably higher than those (∼25–30 %@423 K) of the Mn 4+ activated perovskite NIR phosphors. Luminescence regulation was achieved by substituting La 3+ with Gd 3+ , and it was revealed that Gd 3+ may act as a sensitizer to significantly enhance Cr 3+ luminescence (∼346 % at 77 K) through Gd 3+ → Cr 3+ energy transfer, which was confirmed by spectral and fluorescence lifetime analysis. The observed spectral features and the influence of Gd 3+ were rationalized by considering crystal structure, local coordination, and crystal field. Finally, an NIR pc-LED device showing strong ∼700–900 nm luminescence was fabricated to show potential application of the phosphor in night vision and plant lighting.
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
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Yan Sun,Aowen Chen,Jingdao Yang,Kun Zhang,Sikai Wang,Xuerong Xu,Luyue Niu,Yue Jing,Ci Wang,Jing Ren,Jianzhong Zhang
Expanding gain bandwidth into the L-band for erbium-doped fiber amplifiers (EDFAs) is a crucial strategy to overcome limitations in prevalent C-band focused commercial silica-based EDFAs, significantly boosting optical network transmission capacity. Herein, we synthesized Er 3+ -doped broadband near-infrared emission tellurite glasses utilizing the melt quenching process, systematically exploring the impact of ZnCl 2 on the glass structure and optical properties. The 82TeO 2 –3Nb 2 O 5 –15ZnCl 2 –3Er 2 O 3 (TNZ15) glass emerged as a standout candidate for broadband amplifiers around wavelength at 1.55 μm. With escalating ZnCl 2 concentration, a discernible red shift in the emission peak wave lines was observed, accompanied by an expansion of the full width at half maximum (FWHM) from 98 nm to 106 nm. Noteworthy characteristics of all samples included exceptional thermal stability and elevated near-infrared (NIR) transmittance. Application of the Judd-Ofelt (J-O) theory facilitated the calculation of J-O parameter intensity, providing deeper insights into the optical behavior of the materials. Finally, the evaluation of TNZ15 planar optical waveguides, employing the vertical top pumping mode of two 980 nm LEDs, encompassed both the C-band (1530–1565 nm) and the L-band (1565–1625 nm). The results underscore the potential of TNZ15 glass as a promising gain material for broadband optical amplifiers and lasers, offering valuable insights into the development of next-generation optical amplification technologies.
研究领域:
光学材料
·
光通信
·
物理学
✓ 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）