CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Shuai Zhang,Yifei Zhao,Jiadong Zhou,Hong Ming,Chun-Hai Wang,Xiping Jing,Shi Ye,Qinyuan Zhang
Manganese (II) compounds are promising luminescent candidates for white light-emitting diodes (WLEDs) applications. However, the forbidden d - d transition of Mn 2+ ion makes the absorption of blue light and emission relatively weak without a sensitizer. The strategy of isolating MnX n (X is the ligand) with some ionic liquids is used to design two new hybrid compounds in this study, focusing on the orbital hybridization to relax the parity selection rule of the d - d transition. A large hindrance of the organic cations in the two new Manganese (II) hybrids enables a large Mn-Mn distance (up to ~ 10 Å) to form zero-dimensional (0D) structures, and the Mn sites in both compounds have a low site symmetry ( C 2 or C 1 ). The 0D structure of MnX n polyhedral is beneficial to isolatedly investigate the orbital hybridization of the ligand and Mn 2+ ion. A higher orbital hybridization extent for Mn-Br bond is evidenced by Density Functional Theory (DFT) simulation. This conclusion leads to the strong and stable green light emissions under preferable blue light (460 nm) excitations, giving photoluminescence quantum yields (PLQYs) as high as 76%. The WLEDs fabricated with these compounds have presented high luminous efficiency up to ~130 lm/W and survived multiple stability tests. The research favors the discovery of ideal Mn compounds for displays and lighting applications.
研究领域:
材料科学
·
光电
·
光子学
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2019
·Vol. 48
·期 31
·11791-11802
·
IF 4.052
Baochen Wang,Ruiyu Mi,Yangai Liu,Ming Yu,Zhaohui Huang,Minghao Fang
The luminescence spectra of some trivalent rare-earth ions in a garnet host present interesting multisite structures; however, their mechanism is still not fully understood. In this study, for the first time, we directly observed two luminescence centers of Ce3+ at a single site in a novel garnet Ca3Sc2Ge3O12 phosphor. The spectral characteristics of the two luminescence centers were clearly identified using site-selective and time-resolved spectroscopy. Luminescence excitation was observed at 425 nm and 450 nm, corresponding to emissions at 490 (Ce(I)) nm and 530 (Ce(II)) nm. The decay curves confirmed the existence of energy transfer from Ce(I) to Ce(II). The potential mechanisms of the multisite luminescence are also discussed. This study gives a new insight into the concentration-dependent red-shift and inhomogeneous broadening of the Ce3+ emission band in the garnet phosphor. The title phosphor showed excellent thermal stability, with more than 90% of the initial intensity at the functioning temperature (323 K). Finally, a white LED lamp was fabricated, which exhibited an excellent color rendering index (82.3) and a proper correlated color temperature (3582 K). These results demonstrate that Ca3Sc2Ge3O12:Ce3+ is highly promising to serve as a blue-pumped phosphor for white LEDs.
研究领域:
材料科学
·
光电技术
·
光子学
✓ 已验证
DOI
高影响因子
ACS Photonics
·
2025
·
IF 6.7
Ziwen Wang,Zezhong Yin,Dongze Xie,Yifei Wang,Zhenyu Yang,Fukai Shan,Jia Huang,Dandan Hao
Self-powered photodetectors (SPPDs) have attracted considerable attention due to their low power consumption, low cost, and small size. However, traditional SPPDs typically possess a unipolar photoresponse, which adds complexity to the processing of optical signals. Here, self-powered bipolar photodetectors (SP-BPDs) with a structure of ITO/In2O3/CsBi3I10-IR813/C are fabricated by modifying CsBi3I10 using a near-infrared (NIR) organic dye (IR813, p-toluenesulfonate). The photodetector not only broadens its absorption to the NIR range but also generates a reverse current under illumination with wavelengths exceeding 675 nm. The reversal of the photocurrent polarity is attributed to the competition between the photovoltaic effect of the heterojunction and the photothermoelectric effect of IR813 under different wavelengths of light. The current state of the SP-BPD can be effectively modulated by precisely regulating the wavelength and power density of the incident light. Therefore, five basic all-optical logic gates (“OR”, “AND”, “NOT”, “NOR”, and “NAND”) and encrypted optical communication can be realized in the SP-BPD. This study presents a simple and practical strategy for designing SP-BPDs.
研究领域:
光电子学
·
材料科学
·
光子学
·
通信技术
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE
·
2022
·Vol. 377
·期 6611
·
IF 63.714
Xudong Zhang,Yilin Liu,Jiecai Han,Yuri Kivshar,Qinghai Song
Ultracompact sources of circularly polarized light are important for classical and quantum optical information processing. Conventional approaches for generating chiral emission are restricted to excitation power ranges and fail to provide high-quality radiation with perfect polarization conversion. We used the physics of chiral quasi-bound states in the continuum to demonstrate the efficient and controllable emission of circularly polarized light from resonant metasurfaces. Exploiting intrinsic chirality and giant field enhancement, we revealed how to simultaneously modify and control spectra, radiation patterns, and spin angular momentum of photoluminescence and lasing without any spin injection. The superior characteristics of chiral emission and lasing promise multiple applications in nanophotonics and quantum optics.
研究领域:
纳米光子学
·
量子光学
·
超材料
·
光子学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Chenxu Wang,Lihe Yan,Jinhai Si,Tianyu Huo,Xun Hou
All-inorganic lead halide perovskites nanocrystals (NCs) have been demonstrated to be promising candidates for optoelectronic devices, but preparing perovskite NCs with high photoluminescence quantum yields (PLQYs) and excellent stability has been a challenge. In this work, CsPbBr 3 /Cs 4 PbBr 6 core/shell NCs with a PLQYs of 87.23% and long-term stability in ambient environments was prepared by room temperature inverse microemulsion method. The excellent stability of the sample was attributed to the protection of Cs 4 PbBr 6 , and higher PLQYs could be owing to the passivation effect of the core/shell structure. To illustrate the distribution of photogenerated carrier in the core/shell structure, a confined excitons model was proposed based on time-resolved PL and temperature dependent PL measurements. Femtosecond time-resolved transient absorption spectra measurements were performed upon different excitation wavelength to unveil the photogenerated carrier dynamics in core/shell NCs. Upon 300 nm excitation, a carrier transfer process with the time of 3.18 ps from shell to core layer was observed. Furthermore, both two- and three-photon absorption PL was discovered in core/shell NCs, further verifying the carrier transfer process.
研究领域:
材料科学
·
光电
·
纳米技术
·
物理化学
✓ 已验证
DOI
高影响因子
Optics
·
2020
·Vol. 1
·期 2
·202-212
·
IF 0
Yang Ran,Peng Xiao,Yongkang Zhang,Deming Hu,Zhiyuan Xu,Lili Liang,Bai-Ou Guan
Operando and precisely probing aqueous pH is fundamentally demanded, both in chemical and biological areas. Conventional pH probes, subjected to the larger size, are probably unfit for application in some extreme scenarios, such as a trace amount of samples. In this paper, we have further developed the pH sensor that leverages the microfiber Bragg grating with an ultra-compact size down to an order of magnitude of 10−14m3. Using the electrostatic self-assembly layer-by-layer technique, the functional film consisting of sodium alginate, which harnesses a pH-dependent hygroscopicity, is immobilized on the fiber surface. Consequently, the alteration of aqueous pH could be quantitatively indicated by the wavelength shift of the grating resonance via the refractive index variation of the sensing film due to the water absorption or expulsion. The grating reflections involving fundamental mode and higher order mode exhibit the sensitivities of −72 pm/pH and −265 pm/pH, respectively. In addition, temperature compensation can be facilitated by the recording of the two reflections simultaneously. Furthermore, the modeling and simulation results predict the pivotal parameters of the configuration in sensitivity enhancement. The proposed proof-of-concept enriches the toolbox of pH sensor for catering to the need of detection in some extremely small spaces—for example, the living cells or the bio-tissues.Keywords:fiber optics;microfiber;Bragg grating;sodium alginate;electrostatic self-assembly;pH sensor
研究领域:
生物技术
·
化学工程
✓ 已验证
DOI
Journal of Materials Chemistry C
·
2021
·Vol. 9
·期 46
·16626-16633
·
IF 7.393
Yuzhen Wang,Yanan Wang,Chaoyang Ma,Yanbin Li,Chong Zhao,Wanggui Ye,Zicheng Wen,Xuanyi Yuan,Yongge Cao
Bifunctional luminescence materials have aroused considerable concern due to their wide application and high utilization. In this study, we have successfully integrated bright green up-conversion luminescence of K0.5Bi0.5TiO3 (KBT): Er/In ceramics with potential applications on cryogenic optical thermometry and photomemory. By employing the fluorescence intensity ratio based on thermally coupled levels of Er3+: 2H11/2/4S3/2, the splendid low-temperature sensing properties were demonstrated as the maximum relative sensitivities were 7.14% K−1 and 8.73% K−1 at 137 K for KBT: Er and KBT: Er/In ceramics, respectively. Moreover, the reversible photochromism performance could be triggered by the 365 nm irradiation and vanished by thermal stimulation at 150 °C. Remarkably, the coupling of up-conversion luminescence and photochromism performance has a promising application on rewritable photomemory. For the KBT: Er/In ceramic, the emission intensity could be reduced by 76.59% after coloration, and restored to its original value after bleaching. In order to evaluate the practicability of applying on photomemory, a reversible experiment was designed and successfully executed. It is believed that the KBT: Er/In bifunctional ceramic can be a great candidate for low-temperature sensing and optical information storage devices.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
Crystals
·
2023
·Vol. 13
·期 8
·1273
·
IF 2.7
Huiting Zhang,Zhonghua Zhu,Shengdi Ta,Ninghan Zeng,Limin Wu,Wenxia Wu,Peng Zhang,Shoulei Xu,Bernard Albert Goodman,Wen Deng
High-quality single crystals with empirical composition Y2.96Sm0.04Ga5O12(YGG: Sm3+) were successfully prepared by the optical floating zone method for the first time and compared with related single crystals of Y2.96Sm0.04Al5O12(YAG: Sm3+). With both crystals, XRD showed that Sm3+entered the cubic-phase structure. Optical absorption spectra produced a series of peaks from Sm3+in the 250 nm to 550 nm range, and photoluminescence excitation (PLE) spectra detected at 613 nm showed strong excitation peaks at 407 nm and 468 nm. A strong emission peak at 611 nm (orange-red light) was observed in the photoluminescence (PL) spectra under excitations at both 407 and 468 nm, respectively, but it was much brighter under excitation at 407 nm. Furthermore, with both emission spectra, the peaks from the YGG: Sm3+crystal were significantly more intense than those from the YAG: Sm3+crystal, and both experienced a blue shift. In addition, under excitation at 407 nm, the color purity of the emitted orange-red light of YGG: Sm3+was higher than that of the YAG: Sm3+crystal, and the fluorescence lifetime for the4G5/2→6H7/2transition of YGG: Sm3+was longer than that of the YAG: Sm3+crystal. The optical properties of the YGG: Sm3+crystal are better than those of the YAG: Sm3+crystal.
研究领域:
材料科学
·
光学材料
·
无机化学
·
固体物理
·
发光材料
✓ 已验证
DOI
高影响因子
Laser & Photonics Reviews
·
2021
·Vol. 15
·期 10
·2100278
·
IF 13.138
Qionghua Mo,Chen Chen,Wensi Cai,Shuangyi Zhao,Dongdong Yan,Zhigang Zang
The photoluminescence quantum yield (PLQY) of CsPbBr 3 perovskite nanocrystals (NCs) prepared by the hot-injection method can exceed 90%, which have attracted intensive attention for white light-emitting diodes (WLEDs). However, the whole hot-injection experiment requires air isolation and relatively high temperature. In addition, the poor stability of CsPbBr 3 NCs impedes their applications. Here, a facile method is reported to synthesize CsPbBr 3 @ZrO 2 NCs at room temperature in air. Owing to using ZrO 2 coated CsPbBr 3 NCs, the prepared CsPbBr 3 @ZrO 2 NCs not only present a PLQY of 80% but also exhibit an enhanced stability to heat and moisture. Furthermore, WLEDs are fabricated with CsPbBr 3 @ZrO 2 NCs and commercial red phosphors (CaAlSiN 3 :Eu 2+ ) on blue LEDs chips. The fabricated WLEDs exhibit a correlated color temperature (CCT) of 4743 K and luminous efficacy as high as 64.0 Lm W –1 . In addition, visible light communication with a high data rate of 33.5 Mbps is achieved using the WLEDs. This work provides a room temperature strategy to coat zirconia for CsPbBr 3 @ZrO 2 NCs, benefiting to enhance the optical performance and stability, as well as the promotion of the great potentials in solid-state illuminating and visible light communication applications.
研究领域:
材料科学
·
光学工程
·
纳米技术
✓ 已验证
DOI
高影响因子
OPTIK
·
2021
·
IF 2.443
Xiangyan Yun,Jun Zhou,Yaohui Zhu,Xiong Li,Yetong Jia,Denghui Xu
A novel series of Er 3+ doped LiYbW 2 O 8 phosphors were synthesized by high-temperature solid-state process. Upon 980 nm NIR laser excitation , the up-conversion emission spectra show that the intense green emissions and weak red emissions can be proposed as the transitions of 2 H 11/2 → 4 I 15/2 , 4 S 3/2 → 4 I 15/2 , 4 F 9/2(2) → 4 I 15/2 and 4 F 9/2(1) → 4 I 15/2 of Er 3+ ions, respectively. The optical temperature sensing properties were carefully investigated on the basis of fluorescence intensity ratio (FIR) technology about energy level transitions of 2 H 11/2 → 4 I 15/2 and 4 S 3/2 → 4 I 15/2 in the range from 300 K to 500 K. Moreover, the maximum values of relative sensitivity ( S r ) and absolute sensitivity ( S a ) are separately about 1.62% K −1 at 300 K and 0.64% K −1 at 500 K, which can prove that the sensitivity of LiYbW 2 O 8 :Er 3+ is superior to the latest reported materials for temperature sensors . Results evidence that the Er 3+ doped LiYbW 2 O 8 phosphors can be outstanding candidates for optical temperature sensors with high S r and S a .
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
EXPERIMENTS IN FLUIDS
·
2024
·Vol. 65
·期 9
·1-12
·
IF 2.3
Ulrich Hannah,Weiß Richard,Zigan Lars
This work shows new insights on the application of two-color laser-induced-fluorescence (2c-LIF) thermometry in a droplet chain. A two-dye mixture is used in ethanol, water and ethanol/water mixtures in order to reach a high-temperature sensitivity and avoid the detection of lasing effects in the droplets. Various droplet sizes are recorded in regard to the limitation of the detection system for very small micrometric droplets. The breakup of a droplet chain is measured to assess the spectral detection system in applications with liquid structures of different sizes. Additionally, a proposal to expand the 2c-LIF application for studying ethanol/water droplets regarding mixture composition with a third color channel is presented. Forming two intensity ratios, the spectra can be used to obtain information on the mixture composition of the solvent. Measurements in different ethanol/water mixtures containing 0–100 vol% water are evaluated to show this possibility.
研究领域:
物理化学
·
光学工程
·
流体力学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Sarfraz Ahmad,Shulong Chang,Danni Peng,Wenjin Liu,Kaiying Zhang,Yuan Deng,Lin Dong
Multimode luminescent materials possess diverse optical characteristics and play crucial roles in photocommunication and information security. Force-induced mechanoluminescence, as a distinctive excitation mode, exhibits impressive capabilities in the field of anticounterfeiting and information storage. Here, we integrate mechanoluminescence with the conventional luminescence modes (including up-conversion luminescence, down-conversion luminescence, and thermoluminescence (TL)) within LiNbO3 via well-tuned codoping of Er3+ and Pr3+. LiNbO3:Pr3+/Er3+ exhibits excitation-dependent photoluminescence (PL), enabling tunable emission colors ranging from green to red, while it shows green up-converted PL emissions owing to the electronic transitions of Er3+ ions. Both TL and mechanoluminescence emissions are achieved by employing intertrap levels, where mechanical or thermal stimulation releases carriers that transfer energy to Pr3+ ions, resulting in red emissions. Moreover, an underlying competitive interaction between TL and mechanoluminescence is revealed, which can be leveraged for force/thermo-encored information storage. This unique feature positions LiNbO3:Pr3+/Er3+ as novel recordable information storage labels to monitor the freshness of perishable goods such as food and medicine. In addition, quadra-mode luminescence material LiNbO3:Pr3+/Er3+ provides multidimensional codes via emission color and distribution, indicating its significant potential in advanced anticounterfeiting technology.
研究领域:
材料科学
·
光学
·
信息科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）