最新刊期
卷 45 ， 期 1 ， 2024
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Patterned Vapor Deposited Perovskite Light Emitting Diodes
via Phosphine Oxide Passivation 增强出版 AI导读摘要：Thermal evaporation is promising for bringing perovskite light-emitting diodes （PeLEDs） towards commercial display applications. However， vapor-deposited perovskites exhibit low photoluminescence quantum yield （PLQY） due to unpassivated defect states. Here， we report a method of introducing passivating ligands into perovskites through an in-situ co-evaporation technique. The phosphonate groups coordinated with unsaturated sites， passivating the grain boundary defects in perovskite and suppressing trap states. LED devices based on perovskite films prepared with the optimal ratio exhibited a maximum EQE of 6.3% and a maximum brightness of 35 642 cd/m2. Furthermore， by employing a fully vacuum-based device fabrication process， high-resolution PeLEDs with a maximum EQE of 5.0% at 312 pixels per inch（ppi） were achieved. In conclusion， this study provides useful guidance for defect passivation in thermal-evaporated PeLEDs， demonstrating the great potential and commercial prospects of thermal-evaporation PeLEDs in efficiency and brightness enhancement.关键词：perovskite light-emitting diodes;thermal evaporation;defect passivation;patterning- 648
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发布时间：2024-02-07
Cover Story
- 摘要：As a new type of photothermal nanomaterial， carbon dots （CDs） have attracted extensive attention in tumor therapy. However， limited carbon dots can achieve high photothermal conversion efficiency， especially in the deep red （DR）/near-infrared （NIR） region. Beyond that， the targeting of carbon dots to tumors is also an important issue that we urgently need to solve. In this review， some practical strategies， including size tuning， elemental doping， surface engineering， semiconductor coupling， and biomacromolecule coating， are introduced to enhance the deep red or near-infrared absorption and photothermal conversion efficiency of carbon dots. Based on these strategies， suitable carbon dots or their complexes are constructed to achieve targeted therapy for tumors. Finally， we hope to establish an efficient tumor identification and photothermal therapy system to realize the clinical application of carbon dots. We hope this integrated system has important scientific significance and application value in solving tumor-related problems and promoting health development.关键词：carbon dots;Near-infrared absorption;Photothermal property;Photothermal therapy
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发布时间：2023-11-30 - 摘要：X-ray detection technology has been widely used in medical diagnosis， security detection and scientific research. The direct X-ray detector has higher theoretical detection efficiency， space and energy resolution， and has been widely concerned at home and abroad. Perovskite is an ideal material for direct X-ray detectors because of its large attenuation coefficient， high bulk resistivity， suitable optical band gap and easy large area fabrication. With the increasing demand for detection performance， reasonable device structure design is particularly important. This review introduces the research progress of perovskite direct X-ray detectors from two perspectives： electrode engineering and energy band engineering. Finally， we summarize the research progress and present our views on its future development. We hope this review will provide reference and inspiration for researchers.关键词：perovskite X-ray detector;device structure;Electrode engineering;Energy band engineering;heterojunction
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发布时间：2023-11-14
Invited Review
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Research Progress of Performance of Two-dimensional Organic-inorganic Perovskite Scintillator 增强出版 AI导读
摘要：Two-dimensional （2D） organic-inorganic perovskite materials were widely researched due to their outstanding luminescence performance， and have successfully applied in radiation detection， such as X-ray， γ-ray， and neutron detection and imaging application. The 2D perovskite exhibits excellent scintillation performance even better than commercial scintillator. This paper briefly introduces the physical mechanism of the reaction between radiation and substance， luminescence performance of 2D perovskite， and the luminescence advantage of 2D perovskite compared to conventional scintillator， and summarizes the latest achievement in radiation detection application of 2D perovskite. Finally， we bring out the technology challenge faced for 2D perovskite and the potential solution， and make an outlook for the development tendency in future.关键词：two-dimensional organic-inorganic perovskite;scintillation performance;radiation detection- 221
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发布时间：2023-11-27 - 摘要：Quantum dots（QDs）are widely used in luminescence and display， solar cells， photocatalysis and other fields due to their excellent photovoltaic properties， and its discovery and synthesis won the 2023 Nobel Prize in Chemistry. Micro-LED full-color display technology using quantum dot color conversion does not require mass transfer technology and is expected to achieve large-scale mass production. However， there are still limitations to the performance and lifespan of quantum dots under intense Micro-LED light excitation. Based on， this paper studies the Micro-LED color conversion technology and its characteristics based on quantum dot@ordered mesoporous （QDs@SBA-15） composite materials. The unique pore structure of the ordered mesoporous materials not only can effectively improve the Micro-LED color conversion and light extraction efficiency， but also the dense ordered mesoporous material guarantees the stability of the quantum dots to a certain extent. Firstly， we established a Micro-LED simulation model through the Finite-difference time-domain（FDTD） method to investigate the effects of the particle size of the quantum dots and the pore size of the ordered mesoporous materials on the light extraction efficiency. Based on the guidance of simulation results， QDs@SBA-15 composites were further prepared by physical blending method， characterized by transmission spectroscopy， fluorescence excitation spectroscopy and UV-Vis absorption spectroscopy， and the concentration ratios were determined. Finally， we combined this composite material with polydimethylsiloxane （PDMS） to solidify it into a film and studied its photoluminescence performance. The experimental results showed that the matching degree of the quantum dot particle size and the pore diameter of the mesoporous material， as well as the concentration ratio of quantum dots and ordered mesoporous materials， is crucial to the luminous efficiency of QDs@SBA-15 composite materials and the color conversion performance of Micro-LED. Through the optimization， the resulting composites can obtain excellent luminescence performance and good environmental stability， compared with the pure quantum dots color conversion layer， the light extraction efficiency of the composite material has been improved by 81.73%， and the environmental stability of the composite material has been improved by 14.33%. The color gamut of tri-color devices obtained with Micro-LED as the blue light source reached 104.52% NTSC. This research provides theoretical guidance for quantum dot color conversion Micro-LED display technology， and opens up a new path to realize the full-color Micro-LED.关键词：quantum dots;Ordered mesoporous materials;color conversion;micro-LED
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发布时间：2023-11-30 - 摘要：InP/GaP/ZnS quantum dots were prepared using HF in⁃situ injection method. The influence of HF on the luminescence performance of InP quantum dots was analyzed through testing methods such as UV-Vis-NIR absorption spectrum， Photoluminescence spectrum， transmission electron microscopy， spherical aberration corrected transmission electron microscope， X-ray diffraction and X-ray photoelectron spectroscopy. The experimental results show that HF etching reduces the surface oxidation defect state of quantum dots， effectively controls the oxidation of InP core surfaces， and the atomic ligand form of F- passivates the hanging bonds on the surface of quantum dots， significantly improving the optical performance of quantum dots. The HF-treated InP/GaP/ZnS quantum dots exhibit the best luminescence performance with PLQY reaching up to 96%. In addition， the light emitting diode prepared by treating InP/GaP/ZnS quantum dots with HF has a current efficiency of 6.63 cd/A and an optimal external quantum efficiency （EQE） of 3.83%.关键词：HF;InP/GaP/ZnS quantum dot;optical performance;light emitting diode
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发布时间：2023-11-23 - 摘要：A novel Y-type emitter （TX-TCz） with delayed fluorescence characteristic was designed and synthesized using thioxanthone group as the acceptor and 6-（9H-carbazol-9-yl）-9H-3，9'-bicarbazole moiety as the donor. Theoretical calculations showed the prominent separation of HOMO and LUMO levels with only a small overlap on the benzene ring， which helped to achieve the small energy band gap ΔEST between the S1 and T1. With the increasing polarities of solvents， the emission peaks of TX-TCz exhibited an obvious red shift and dual emission peaks generated because of the coexistence of charge transfer state and locally excited state. In the pure film， the emission peak of TX-TCz was located at 513 nm with the photoluminescence quantum yields （PLQY） of 11.5%. According to the fluorescence and phosphorescence emission at low temperature， ΔEST of 0.03 eV between S1 and T1 was calculated， at the same time μs magnitude lifetime was also detected. It indicated that TX-TCz had the considerable delayed fluorescence characteristic. In addition， TX-TCz had good thermal stability and electrochemical properties， which was helpful for the preparation of high-performance OLED devices. In the doped devices with the doping concentration of 5%（wt）， TX-TCz showed excellent blue light performance with the emission peak at 463 nm and the maximum external quantum efficiency （EQE） of 1.53%. In the non-doped device， good green emission at 522 nm was obtained with a maximum EQE of 1.81%关键词：OLED;Y-type structure;blue/green light;delayed fluorescence
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发布时间：2023-11-30 -
Efficient and Long Lifetime Blue Light Material Based on Anthracene[2,3-
b ]benzofuran Framework 增强出版 AI导读摘要：A novel compound with anthracene［2，3-b］benzofuran as the core was designed and synthesized， and the compound was obtained by modification with the donor carbazole group as 2-（anthracene［2，3-b］benzofuran-3-yl）- 9-phenyl-9H-carbazole （ABPCz）. Studies of doped devices show that， ABPCz can realize blue light emission， the maximum current efficiency of 8.79 cd/A and the maximum external quantum efficiency（EQEmax） of 7.8%. The peak spectrum is 448 nm， and there is a strong shoulder at 476 nm， as well as a Commission Internationale de l'Eclairage （CIE） coordinate of （0.17， 0.23）.The test device LT90 （brightness decays to 90% of the initial brightness） has a lifetime of 153 h at an initial brightness of 1 000 cd/m2. The results show that anthracene［2，3-b］benzofuran can be modified with carbazole groups to obtain high-efficiency and long-life blue-light devices， which provide a new direction for the design and development of high-performance blue-light materials.关键词：organic electroluminescence;anthracene［2，3-b］ benzofuran;blue light;fluorescent material- 190
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发布时间：2023-11-30 -
Synthesis and Luminescence Properties of Submicron K2SiF6∶Mn4+ Red Phosphor by Precipitation Method 增强出版 AI导读
摘要：Sub-micrometer-sized K2SiF6∶Mn4+ phosphors hold transformative potential in the Micro-LED display industry. However， the synthesis of small-diameter K2SiF6∶Mn4+ phosphors remains a challenge due to immature technology， hindering efficient luminescence at the sub-micrometer scale. This paper introduces a novel method for synthesizing sub-micrometer-sized K2SiF6∶Mn4+ phosphors via precipitation. Fluorescence spectroscopy analysis reveals that the phosphor displays typical Mn4+ red emission under 450 nm blue light excitation， with an internal quantum efficiency reaching 94.9%. SEM observation indicates that the synthesized phosphor particles exhibit a size distribution between 150 nm and 450 nm. The phosphor demonstrates excellent thermal quenching performance， maintaining 102% of the initial luminescence intensity at 443 K. A white LED was fabricated by combining green phosphor β-sialon∶Eu2+ and K2SiF6∶Mn4+ and applying it to a blue chip. The color gamut coverage achieved 133% NTSC， and the color temperature and color rendering index fluctuated by approximately 10% and 2% respectively when the driving current increased from 10 mA to 120 mA， indicating overall stable performance. This paper offers fresh insights into the synthesis of sub-micrometer-sized K2SiF6∶Mn4+ phosphors， contributing to the advancement of Micro-LED display technology.关键词：phosphor;Submicron-size;Mirco-LED;Synthesis- 238
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发布时间：2023-11-21 - 摘要：With the continuous improvement of people's requirements for the quality of lighting sources， a single indicator parameter cannot fully satisfy the evaluation of LEDs. This study investigates the effects of phosphor ratio and emission wavelength on the color rendering index， the blue light hazard ratio of spectral power distribution， spectral continuity， and light efficiency of white light LEDs. The results show that the appropriate phosphor type and ratio can reduce the secondary absorption between phosphors， energy loss， light attenuation， and spectral distortion， thereby improving the quality of white light LEDs. Moreover， different wavelengths of blue light LED excitation phosphors offer distinct advantages. By combining them， it is possible to improve the white light LED's color index， spectral continuity， and reduce the blue light hazard ratio of spectral power distribution. In this study， commercially available 450 nm and 460 nm blue light LED chips were employed to emit the optimized phosphor， resulting in a significant improvement in the quality of white light LEDs. The color index， blue light hazard ratio of spectral power distribution， spectral continuity， and light efficiency were measured as 97.4， 26.3%， 93.6% and 98.75 lm/W， respectively. This research provides a comprehensive reference for the production of high-quality white light LEDs， which can contribute to the widespread adoption of high-quality white light LEDs.关键词：high quality LED;emission wavelength;phosphor ratio
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发布时间：2023-11-21 - 摘要：With the development of soft glass fiber and fiber laser， more and more researchers use soft glass fiber instead of quartz fiber to obtain high power mid-infrared supercontinuum source. Through extensive reading of the domestic and foreign literatures on supercontinuum generation in soft glass fibers such as fluoride， chalcogenide and tellurite glass fibers， the recent progress in the generation of mid-infrared supercontinuum source using these three types of fibers is reviewed. At present， fluoride glass fiber is widely used in the experiment， with the rapid progress in research and development. The spectrum coverage range of mid-infrared supercontinuum source is 2~5 μm， and the maximum output power is 30 W. The bandwidth of the mid-infrared supercontinuum source generated by chalcogenide glass fiber can reach more than 10 μm， but the output power is low. Because the hydroxyl groups in tellurite glass fibers are difficult to be removed， the progress in the experiment of mid-infrared supercontinuum is very slow. In recent years， the development of fluorotellurite fiber is rapid， and it may become an ideal medium for the future study of mid-infrared supercontinuum.关键词：supercontinuum spectrum;mid-infrared;soft glass fiber;Nonlinear optical fiber
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发布时间：2023-11-30
Synthesis and Properties of Materials
- 摘要：3 μm laser is located in the molecular fingerprint region and has important application value in fields such as medical surgery， gas detection，and military applications. Er3+∶ZBLAN fiber laser has the advantages of high efficiency and integration， making it the main output mode of 3 μm laser. Starting from the generation of 3 μm laser by erbium ion transition， this article introduces the structural principle and energy level system of 3 μm laser generation， summarizes the technical solutions and research progress for achieving high-power continuous output and pulse output in this band， with a focus on the experimental research of Q-switched and mode-locked lasers based on saturable absorbers of different materials. And analysis of the problems is solved in order to achieve high power output in the 3 μm band. Finally， the development direction of Er3+∶ZBLAN lasers is prospected.关键词：3 μm laser;Er3+-doped fiber;fiber lasers;pulsed laser
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发布时间：2023-11-23 - 摘要：Near-infrared （NIR） detection technology plays an important role in military， communications and industrial applications. The huge market demand has led to a rapid development of research in NIR photodetectors （PDs）. Rare earth doped upconversion nanoparticles （UCNPs） with two- or multi-photon pumping characteristics can convert NIR photons to visible or ultra-violet photons and be absorbed by semiconductors with wider bandgaps， producing upconversion PDs with excellent performance. However， the implementation of NIR narrowband upconversion PDs still faces several difficulties， such as rare earth ion fluorescence quantum low efficiency， and the need for high pumping thresholds to achieve detectable upconversion luminescence. Herein， we utilized NaYF4∶4%Er UCNPs combined with perovskite semiconductor layers to achieve a narrowband upconversion PDs of 1 550 nm. Upconversion luminescence of UCNPs is enhanced by using Ag nanorods （NRs） layers with localized surface plasmon resonance effect， thus lowing the pump threshold of the upconversion PDs. The optimized responsivity （R） and detectivity （D*） of Ag NRs/NaYF4∶4%Er UCNPs/MAPbI3 hybrid upconversion PDs are ~48.5 mA/W and 5.7
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发布时间：2023-11-23 -
Output Characteristics of SESAM Mode-locked All-polarization-maintaining（PM） Picosecond Fiber Laser 增强出版 AI导读
摘要：An all-polarization-maintaining picosecond fiber laser mode-locked by a semiconductor saturable absorber mirror（SESAM） is constructed. The effects of different SESAM structure with multi-quantum well and bulk material as saturable absorber layer on the output characteristics are analyzed and compared. The experimental results show that both the multi-quantum well and the bulk material SESAM can achieve stable self-starting mode-locking. The SESAM modulation depth increases with the number of quantum well periods， resulting in narrower laser output pulse width， higher output power， and a larger mode-locking range. However， the greater the number of quantum well periods， the more nonsaturable losses of the SESAM， and it will reduce the output power at the same pump power. At the same modulation depth， bulk material SESAM has more nonsaturable losses， which will reduce the output power and optical to optical conversion efficiency， but it has a more significant effect on pulse narrowing. The wavelength and spectral width of the output pulses are not significantly affected by the SESAM， but they are primarily controlled by the fiber Bragg grating（FBG）. This study provides valuable guidance for the design and the selection of the SESAM.关键词：fiber laser;semiconductor saturable absorber mirror;ultrashort pulse;output characteristic- 120
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发布时间：2023-11-21
Device Fabrication and Physics
- 摘要：The emerging technique of liquid biopsy opens up a new opportunity for the rapid and accurate diagnosis of melanoma tumor featuring high metastatic tendency and mortality rates. However， the accuracy and sensitivity for liquid biopsy of melanoma are still limited， due to the use of low-expression epithelial cell adhesion molecule（EpCAM） to achieve enrichment of circulating tumor cells（CTCs） and subaltern photoluminescence quantum yields（PLQYs） organic probes as signal indicators. Here， we construct a new strategy of CTCs detection for liquid biopsy of melanoma by employing high-PLQYs metal halide perovskite（MHP） quantum dots and melanoma-derived exosome（MEX） as signal indicators and recognition analytes， respectively. The synthesized composites（PSPE） exhibit the superiorities on perfect hydrophilicity and hypotoxicity. In contrast to commercial EpCAM-triggered products， the detection sensitivity of our reagent materials is raised up by an order of magnitude. All results predict the potential of exosome-triggered MHP-mediated CTCs detection in accurate melanoma diagnosis of liquid biopsy.关键词：melanoma;exosome;circulating tumor cells;metal halide perovskite;liquid biopsy
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发布时间：2023-11-16 - 摘要：The excessive use of metal ions can not only cause environmental pollution but also endanger human health. So， detecting heavy metal ions is crucial but challenge to reach. Luminescent metal-organic frameworks（LMOFs） have been considered as simple， effective， and promising fluorescent sensing materials due to their advantages of high color purity， ultra-high porosity， and tunable structure. Herein， we chose 3，5-bis（4-imidazol-1-yl）pyridine（Bip） as the main ligand， 1，4-naphthalene dicarboxylic acid（1，4-ndc） as the auxiliary ligand， and Ni2+ as the central ion to synthesize a two-dimensional planar MOF ［Ni2（Bip）2（1，4ndc）2（H2O）6］（CUST-756， in which CUST is the abbreviation of Changchun University of Science and Technology）using a solvothermal method， and Eu3+@ CUST-756 composite materials have been prepared through post modification method. The characterizations of CUST-756 and Eu3+@CUST-756 composite materials such as PXRD， FT-IR and XPS also have been carried out. The luminescence characteristics， metal ion sensing performance and mechanism of Eu3+@CUST-756 composite materials were studied via fluorescence spectroscopy. The experimental results show that Eu3+@CUST-756 has excellent luminescence performance and good stability in methanol solution. The introduction of Eu3+ makes the material suitable for the detection of metal cations Cr3+ and Fe3+， with a detection limit（LOD） of 5.44 μmol·L-1 for Cr3+ ions. The LOD of Fe3+ ions is 7.51 μmol·L-1， which has performance similar to most LMOFs.关键词：metal-organic frameworks;post-modified method;fluorescence detection
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发布时间：2023-11-30 - 摘要：Real-time and convenient pH detection plays an important role in environmental monitoring， medical diagnosis and other fields. In this paper， a ratiometric fluorescent capillary-based pH sensor was prepared by sol-gel method. The sodium 8-hydroxy-pyrene-1，3，6-trisulfonate （HPTS） acts as a pH sensitive fluorescent probe， and combines with hexadecyl trimethyl ammonium bromide （CTAB） to form HPTS-IP ion pairs. Then the ion pairs were dispersed in the sol-gel， and further fixed in the inner wall of capillary to obtain the ratiometric fluorescent capillary pH sensor. Based on the dual excitation bands of HPTS， the referenced excitation ratiometric sensor is realized. When the pH value rises from 5 to 8， the fluorescence intensity ratio of HPTS gradually increases with the increase of pH， with a pKa value of 6.95. By analyzing the changes in fluorescence intensity ratio of HPTS， pH can be indirectly detected. This sensor has high pH sensitivity， good stability， and excellent reversibility， which can be applied quickly， flexibly， and conveniently in practical operations. All in all， it is promising in pH monitoring at environmental protection and biomedical fields.关键词：fluorescence probe;optical sensor;pH detection;capillary;ratiometric fluorescence
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发布时间：2023-11-17
Luminescence Applications and Interdisciplinary Fields
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