最新刊期
      卷 45 ， 期 7 ， 2024

        Cover Story

      • “最新研究突破：单电极电致发光纤维，通过无线驱动实现可视化传感，具有低成本、高灵敏度和柔软性，为智能穿戴和生物检测领域带来创新应用。”
        YANG Xiaorui,YANG Weifeng,LI Kerui,LI Yaogang,ZHANG Qinghong,WANG Hongzhi,HOU Chengyi
        Vol. 45, Issue 7, Pages: 1049-1057(2024) DOI: 10.37188/CJL.20240067
        摘要：The advent of flexible electronics， smart sensors， and intelligent wearables has catalyzed a burgeoning interest in flexible electroluminescent devices. These devices， particularly electroluminescent fibers， are distinguished by their portability， malleability， and integrability into textiles， offering substantial promise for advancements in visual sensing technology. However， due to their mostly dual-electrode structure and complex fabrication process， there are still shortcomings in terms of cost， device uniformity， sensitivity， and flexibility. This paper develops a single-electrode electroluminescent fiber and achieves continuous preparation of electroluminescent fibers through a simple， scalable， and low-cost manufacturing process. Electroluminescence is achieved through wireless driving. The single-electrode fiber receives energy from the wireless radio field and forms a closed loop with the wireless transmission source through the ground wire to the earth， thus eliminating the dependence on external power sources. The single-electrode electroluminescent fiber consists of a conductive layer， a dielectric layer， and a luminescent layer， with a luminescent wavelength of 456 nm. It has good mechanical performance， luminescent performance， and flexibility. We applied it to the visualization sensing of solutions， and its luminescent intensity can achieve a recognition degree of 0.001% （mass fraction） for sodium chloride concentration， demonstrating excellent sensitivity and significant implications for sweat detection and biology. We further weaved it into luminescent fabrics， which have comparable breathability and mechanical properties to ordinary commercial fabrics and can achieve visual sensing of different concentrations of sodium chloride. In the domain of wearable technology， wirelessly driven single-electrode electroluminescent fibers have enormous potential to achieve visual display and communication functions.  
        关键词：intelligent fibers;visual sensing;continuous preparation;wireless driving   
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        发布时间：2024-04-30

        Synthesis and Properties of Materials

      • “最新研究进展显示，溶胀法在制备荧光微球领域具有调控性强、操作简单等优势。专家深入探讨了溶胀法的基本原理、步骤及影响因素，为优化荧光微球性能提供了改进策略，展望了其应用前景。”
        CHEN Hongjian,YUAN Yuwen,LING Shisheng,CHEN Dong,QIAO Xusheng,DONG Yubing,FAN Xianping
        Vol. 45, Issue 7, Pages: 1058-1067(2024) DOI: 10.37188/CJL.20240079
        摘要：Swelling method is widely used as a method for preparing fluorescent microspheres with strong controllability， simple operation and high practicability. This paper reviews the research progress of preparing fluorescent microspheres by swelling method， expounds the basic principle and steps of preparing fluorescent microspheres by swelling method.It further summarizes the common factors affecting the performance of microspheres during swelling process， such as the types of polymer matrix， fluorescent substance and swelling agent. The improvement strategy of swelling method for optimization of fluorescent microspheres is summarized， and the application prospect of fluorescent microspheres prepared by swelling method is prospected.  
        关键词：swelling method;fluorescent microspheres;research progress;luminous enhancement   
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        发布时间：2024-05-11
      • “在红光放大自发辐射领域，研究者通过A位取代和表面钝化，实现了Cs0.7FA0.3PbI2Br钙钛矿薄膜的低阈值和高稳定性，为红光激光应用提供了新方案。”
        WANG Liang,YAN Mengtong,LI Yan,LYU Mei,LU Hongbo,ZHU Jun
        Vol. 45, Issue 7, Pages: 1068-1076(2024) DOI: 10.37188/CJL.20240075
        摘要：Lead halide perovskite has shown great potential as a new generation of optoelectronic materials due to its adjustable optical band gap， high luminous color purity， high carrier mobility， and solution-processibility. Currently， amplified spontaneous emission （ASE） and laser have been realized in the blue， green， red， and even infrared ranges for perovskite material. As a red light-emitting optical gain medium， CsPbI2Br perovskite material has good thermal stability and a suitable optical band gap and has attracted extensive attention from researchers. However， CsPbI2Br films prepared by the solution method are prone to phase transition in high-humidity environments， and there are many defects in the films， which hinder their further development. To improve the phase stability of CsPbI2Br perovskite films， the A-site is partially substituted by FA+（CH4N2+） in this work. The tolerance factor of the perovskite structure is increased after FA+ substitution， which can effectively improve the phase stability of the perovskite films. Meanwhile， the morphology and crystallinity of the perovskite films are improved. To reduce the non-radiative recombination caused by the surface defects， polymethyl methacrylate （PMMA） is used to passivate the surface of the perovskite films. The C==O bond in PMMA can effectively bind to the undercoordinated Pb2+ on the surface of perovskite， resulting in a good defect passivation effect and effective inhibition of non-radiative recombination. Thanks to the improvement of the film morphology caused by FA+ cation and the PMMA passivation， a low-threshold， 15 μJ/cm2 under nanosecond laser excitation is achieved for the red ASE of the Cs0.7FA0.3PbI2Br perovskite film. At the same time， the film has good hydrophobicity and photostability. Under the air humidity environment （RH （40 ± 10）%）， the ASE intensity remains at 93% of its initial value after a pulsed laser irradiation of 3 000 μJ/cm2 for 120 min. This work provides a reference for realizing low-threshold and high-stability red ASE and laser.  
        关键词：perovskite;amplified spontaneous emission;cationic substitution;Defect passivation   
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        发布时间：2024-05-06
      • “最新研究突破：室温下成功制备发光性能优异的双相CsPbBr3/Cs4PbBr6钙钛矿纳米晶复合薄膜，显著提高水稳定性和空气稳定性，成功应用于白光LED器件。”
        JIANG Dongliang,ZHANG Guoxing,ZHU Xinghua,LI Yuan,CHEN Yan
        Vol. 45, Issue 7, Pages: 1077-1085(2024) DOI: 10.37188/CJL.20240081
        摘要：Synthesis of all-inorganic CsPbX3 （X=Cl， Br， I） perovskite nanocrystals （PNCs） typically requires high-temperature conditions and the involvement of inert gases， which severely hinders their practical application. In this work， a room-temperature method using a 2-methylimidazole ligand to regulate recrystallization was first employed to successfully prepare biphase CsPbBr3/Cs4PbBr6 PNCs with superior luminescent properties. Subsequently， these nanocrystals were combined with various polymers to fabricate nanocrystal composite films. The biphase perovskite structure within the polymers was confirmed through XRD， TEM， and UV-Vis absorption spectroscopy. The CsPbBr3/Cs4PbBr6@PDMS and CsPbBr3/Cs4PbBr6@EVA composite films were identified as having excellent overall performance， and they were encapsulated in LED devices. With dual protection from Cs4PbBr6 PNCs and the polymers， the CsPbBr3/Cs4PbBr6@PDMS exhibited a photoluminescence quantum yield （PLQY） exceeding 80%， while the water stability and air stability of CsPbBr3/Cs4PbBr6@EVA were significantly enhanced. Finally， the CsPbBr3/Cs4PbBr6@EVA composite film was successfully applied to white LED devices， emitting standard white light with a CIE chromaticity coordinate of （0.331， 0.332）.  
        关键词：ligand regulation;CsPbBr3/Cs4PbBr6;composite film;white LED device   
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        发布时间：2024-07-25
      • “最新研究突破：通过调整热激子材料C3的主体及客体浓度，成功制备出色域可调的高效OLED器件，为显示、照明和光电应用带来新机遇。”
        CHEN Mengliang,SHEN Ke,ZHAO Yangkai,SONG Linyi,QIAN Yan
        Vol. 45, Issue 7, Pages: 1086-1094(2024) DOI: 10.37188/CJL.20240091
        摘要：High-efficiency organic light-emitting diodes （OLEDs） with adjustable gamut have brought new possibilities for display， lighting and optoelectronic applications due to their wide color range. In this work， a series of OLEDs featuring adjustable color coordinates have been fabricated simply by modulation of both host and guest concentrations， using the hot exciton material C3 as the single luminescent emitter. At a low doping concentration of 2.5%， the C3 molecule in OLEDs exhibits multiple emissions from all its three excited states. Devices L1 and L3， respectively employing single-host and double-host configurations， achieve warm white and cold white light emissions correspondingly. Their CIE coordinates are （0.298， 0.381） and （0.241， 0.329）， respectively， at an operating voltage of 17 V. At a higher doping concentration （10%）， the emission from the second singlet state predominates， resulting in yellow-green and green emitting light in single-（L2） and double-host （L4） devices， respectively. Notably， owing to better carrier balance， the dual-host device demonstrated a lower turn-on voltage， improved device efficiency， and reduced efficiency roll-off compared to its single-agent device. Due to the hot exciton mechanism which facilitates high-energy-level reverse intersystem crossing， device L4 presents a maximum EQE of 5.36%， surpassing the theoretical upper limit of traditional fluorescent EQE （5%）. This work provides a new approach for designing color-tunable and white OLEDs based on a single fluorescent emitter.  
        关键词：Color gamut adjustable;organic light-emitting diodes;hot exciton materials   
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        发布时间：2024-07-25
      • “采用水热法制备的Sb3+/Ln3+共掺Cs2NaYCl6无铅双钙钛矿材料，成功实现紫外光激发下的宽带自陷激子发光及稀土离子特征发射，为夜视成像系统光源提供新选择。”
        LIU Bo,XU Sai,CHANG Jianglong,LI You,CHEN Baojiu
        Vol. 45, Issue 7, Pages: 1095-1103(2024) DOI: 10.37188/CJL.20240085
        摘要：Cs2NaYCl6 lead-free double perovskite materials doped with Sb3+/Ln3+ （Ln=Nd， Ho， Er， Tm） were successfully prepared by hydrothermal method. The structure and morphologies were studied through X-ray diffraction and scanning electron microscopy. By measuring the photoluminescence spectra， photoluminescence excitation spectra， and fluorescence decay curves， the luminescence and energy transfer mechanisms were discussed. The experimental results show that under UV excitation， Cs2NaYCl6 matrix material can generate broadband self-trapped exciton （STEs） luminescence after doping with trace amounts of Sb3+. Further doping with rare earth ions， under excitation at 320 nm， characteristic emission peaks of rare earth ions in the visible and near-infrared regions can be observed. It is confirmed that there is energy transfer between STEs and rare earth ions， through analysis of the emission spectrum and fluorescence decay curves. Finally， the prepared fluorescent powders were directly physically mixed and coated onto a commercial 340 nm ultraviolet LED chip to prepare a wide coverage near-infrared LED， the near-infrared emission band covers 800-1 600 nm. The use of fluorescent powder conversion LEDs greatly simplifies the construction of near-infrared devices and reduces production costs. It is flexible， compact， convenient， and wide-covered in the near-infrared band， which well meets the requirements of night vision imaging system light sources.  
        关键词：double perovskites;rare earth ions doping;energy transfer;near-infrared LED   
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        发布时间：2024-07-25
      • “最新研究揭示了Lu3+掺杂Na5Y9F32∶Ho3+/Yb3+/Ce3+单晶体在980 nm激光激发下的上转换发光特性，发现随着Lu3+掺杂浓度的增加，红光强度增强而绿光和近红外光减弱，为热敏材料研究提供了新思路。”
        XU Yisong,FANG Lizhi,XIA Haiping,ZHOU Xiong,SONG Hongwei
        Vol. 45, Issue 7, Pages: 1104-1113(2024) DOI: 10.37188/CJL.20240104
        摘要：Lu3+ （mole fraction 0， 0.6%， 1.2%， 1.8%） doped Na5Y9F32∶Ho3+/Yb3+/Ce3+ single crystals were grown using a sealed Bridgman method. When excited by 980 nm LD， up-conversion emissions at 543 nm （5S2/5F4→5I8）， 656 nm （5F5→5I8） in red， and 750 nm （5S2/ 5F4→5I7） in near-infrared were observed. The two-photon transition processes leading to these emissions were identified by analyzing changes in luminescence intensities with varying excitation light intensities. Furthermore， the impact of Lu3+ ion doping concentration on both up-conversion luminescence intensity and fluorescence lifetime was investigated. The 656 nm red emission in the crystal was gradually enhanced as the Lu3+ doping concentration increased from 0 to 1.8%. Conversely， the green emission at 543 nm and near-infrared at 750 nm decreased. The ratio between red and green intensity increased from 0.01 to 1.55， while the fluorescence lifetime of 543 nm decreased from 1.29 ms to 0.99 ms. The incorporation of Lu3+ ions replaces the lattice sites of Y3+ ions， altering the local field environment of the crystal， resulting in changes in the up-conversion luminescence. The maximum absolute sensitivity and relative sensitivity of 1.8% Lu3+ doped Na5Y9F32∶Ho3+/Yb3+/Ce3+ single crystal in the range of 298-448 K were 0.242%·K-1 and 0.217%·K-1， respectively.  
        关键词：Na5Y9F32 single crystal;enhanced red up-conversion emission;Ho3+/Yb3+/Ce3+;Optical temperature sensing;energy transfer   
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        发布时间：2024-05-17
      • “最新研究揭示了一种新型稀土掺杂荧光粉，通过高温固相法制备，具有多色显示效果，有望应用于多色荧光防伪与调控技术。”
        ZHANG Haoqi,DING Qingyang,CHEN Fayi,MIAO Yuqing,YU Dechao,ZHANG Dawei
        Vol. 45, Issue 7, Pages: 1114-1122(2024) DOI: 10.37188/CJL.20240105
        摘要：Study on high-performance multicolor luminescent materials activated by rare-earth ions is the necessary foundation for developing advanced fluorescent anti-counterfeiting techniques. In this paper， a series of Tb3+-doped Mg7Ga2GeO12 phosphors were prepared by a traditional high-temperature solid-state method. With the help of X-ray powder diffraction （XRD）， scanning electron microscopy （SEM）， and energy-dispersive X-ray spectroscopy （EDS）， phase identification， particle size and morphologies， and element mapping were systematically characterized and analyzed. All the results verified the successful preparation of well-crystallized pure phase Mg7Ga2GeO12∶x%Tb3+ powders with irregular shapes and micrometer size distribution. Under excitation of 377 nm， the Mg7Ga2GeO12∶Tb3+ sample efficiently produced several typical blue-green emission bands， respectively increasing to maximum values at 20%Tb3+. Interestingly， there surprisingly presents a single red emission band around 660 nm， disaccording with any electronic transitions of Tb3+. On basis of inductively coupled plasma mass spectrometry （ICP-MS）， steady/dynamic fluorescence spectra， as well as literature investigation， it was proved that the red ~ 660 nm emission is from Mn4+ 2Eg →4A2g transitions and the Mn impurity element was introduced from the raw materials. However， just benefiting from the combined luminescence properties of Tb3+ and Mn4+ ions， the Mg7Ga2GeO12∶Tb3+ sample behaved tunable photoluminescence in response to the excitation-wavelength in 200-420 nm， which can display cyan， green， yellow， white and red colors for much distinguishable observations. These results would consolidate the fundamental materials and techniques for applications in multicolor fluorescent anti-counterfeiting.  
        关键词：phosphors;Tunable excitation;Multicolor emission;fluorescent anti-counterfeiting;Tb3+ ion   
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        发布时间：2024-07-25
      • “最新研究突破荧光玻璃散热难题，通过引入MgO颗粒，显著提升发光性能和均匀性，实现高品质激光驱动白光光源。”
        XU Tao,ZHU Qiangqiang,WANG Guojuan,ZHAI Yue,ZHANG Hong,WANG Le
        Vol. 45, Issue 7, Pages: 1123-1133(2024) DOI: 10.37188/CJL.20240094
        摘要：Phosphor-in-glass （PiG） materials have great potential in the field of laser lighting. However， the low thermal conductivity of the glass matrix leads to serious thermal quenching issues under working conditions， thus reducing the luminous performance. To improve the heat dissipation performance of PiG， high thermal conductivity MgO particles have been introduced into La3Si6N11∶Ce3+ （LSN∶Ce3+） nitride PiG to create MgO-LSN∶Ce3+ composite PiG. By optimizing the fabrication process， MgO content， and glass thickness， the composite PiG with the best comprehensive performance achieved a luminescent saturation threshold of 2.08 W/mm2 under laser excitation， which is 38.7% higher than the MgO-free PiG sample （1.5 W/mm2）. The maximum luminous flux also increased by 44.6%， from 383 lm to 554 lm. Furthermore， due to the improved scattering performance， the luminous uniformity of MgO-LSN∶Ce3+ composite PiG was significantly optimized. Finally， by further introducing red-emitting CaAlSiN3∶Eu2+ （CASN∶Eu2+） phosphors into the composite PiG and adjusting the ratio between LSN∶Ce3+ and CASN∶Eu2+， a high-quality laser-driven white light source with a color rendering index （Ra） of 85.5 can be achieved.  
        关键词：laser lighting;Nitride phosphor;phosphor-in-glass;Heat dispersion;Light uniformity   
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        发布时间：2024-07-25
      • “在食品科学、信息安全、生物医疗等领域，近红外光源研发取得新进展。专家在氟硅酸盐玻璃体系中成功析出钙钛矿型KMgF3纳米晶体，实现高效超宽带近红外发射，为设计低成本、高效率光源提供基础数据。”
        LAI Junhuan,CHEN Long,LIU Xueyun
        Vol. 45, Issue 7, Pages: 1134-1144(2024) DOI: 10.37188/CJL.20240097
        摘要：The growing interest of near-infrared （NIR） spectroscopy in food science， information security， and biomedicine and other important national economy and people’s livelihood fields， has put forward higher demand for NIR light source. It is consequently becoming an important and urgent task to develop near-infrared light sources with highly efficient ultra-broadband emission. In this paper， perovskite KMgF3 nanocrystals were successfully precipitated from a fluosilicate glass matrix SiO2-K2CO3-KF·2H2O-MgF2 via a melt quenching technique. By varying content of SiO2， K2CO3， and MgF2 and heat treatment temperature， the precipitation of KMgF3 nanocrystals can be controlled， and thus glass ceramics with optimized crystallization and transparency were obtained. The crystallized KMgF3 nanocrystals in the glasses provide a stable octahedral coordination and low phonon energy environment for Cr3+ and Ni2+. Under 450 nm blue light excitation， dual-broadband NIR emission originating from Cr3+ （700-1 200 nm） and Ni2+ （1 400-1 700 nm） is achieved based on the energy transfer from Cr3+ to Ni2+. The relative intensity of the NIR-emitting bands varies with the concentration of doping ions. Energy transfer behavior from Cr3+ to Ni2+ is demonstrated according to the measured emission spectra and decay curves， showing a maximum energy transfer efficiency of 52.2%. The energy transfer mechanism can be attributed to electron dipole-quadrupole interaction. The research results not only provide reference data for systematically understanding the regulation of ultra-broadband luminescence of transparent optical materials， but also contribute to the exploration of cost-effective and efficient broadband NIR light source.  
        关键词：glass ceramics;fluoride nanocrystals   
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        发布时间：2024-07-25
      • “最新研究发现，通过聚乙烯亚胺包覆氧化锌纳米颗粒，可有效提高有机太阳能电池的空气和紫外稳定性，为实现高稳定太阳能电池提供新策略。”
        SONG Haitao,WANG Yu,YANG Jiansheng,ZHANG Xiaoke,WANG Zhongqiang,WANG Hua,YANG Yongzhen,WEI Changting,YAN Lingpeng
        Vol. 45, Issue 7, Pages: 1145-1155(2024) DOI: 10.37188/CJL.20240096
        摘要：The interfacial layer materials situated between the active layer and electrodes are critical aspect of organic solar cells （OSCs）， as they directly affect device performance and stability during operation. Zinc oxide （ZnO） nanoparticles （NPs） are commonly functioned as electron transport layer （ETL） materials. However， their high surface defect states and susceptibility to adsorbing water and oxygen can significantly impact the efficiency and stability of OSCs. To tackle this issue， a synergistic approach was adopted in this study by employing polyethyleneimine （PEI）-coated ZnO NPs to passivate surface defects and regulate energy levels. The resulting ZnO@PEI NPs was successfully synthesized using a hydrothermal method and served as an ETL in PM6∶BO-4Cl∶PC61BM-based OSCs. The experimental results indicate that the photovoltaic devices prepared using ZnO@PEI NPs as the ETL exhibit a slight decrease in the power conversion efficiency （PCE）. However， due to the encapsulated PEI effectively passivating the surface defects of ZnO， the ZnO@PEI NPs devices demonstrate enhanced air and ultraviolet stability. In conclusion， this study proposes an effective strategy for developing multifunctional and highly stable ETL， presenting a new and practical approach to achieving highly stable OSCs.  
        关键词：organic solar cells;electron transport layer;Zinc oxide nanoparticle;Polyethyleneimine;Air stability;Ultraviolet stability   
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        发布时间：2024-07-25

        Device Fabrication and Physics

      • “In the field of deep ultraviolet light-emitting diodes (DUV-LEDs), researchers have made significant progress by investigating the use of separated multiple quantum barrier electron blocking layers (EBL). This innovation has been confirmed to increase hole concentration and radiative recombination rate, significantly enhancing device performance by improving hole injection efficiency and suppressing electron leakage.”
        SHEN Guowen,LU Lin,XU Fujun,LYU Chen,GAO Wengen,DAI Guangzhen
        Vol. 45, Issue 7, Pages: 1156-1162(2024) DOI: 10.37188/CJL.20240045
        摘要：Separated multiple quantum barrier electron blocking layer （EBL） have been investigated to improve the performance of AlGaN-based deep ultraviolet light-emitting diodes （DUV-LEDs） with the wavelength shorter than 250 nm. It is confirmed that the DUV-LEDs with separated multi-quantum barriers EBL contribute to a much higher hole concentration and radiative recombination rate than the conventional block EBL configuration. Due to the formation of a hole acceleration zone by the separation interlayer in the EBL， the hole injection efficiency is significantly increased. Meanwhile， the multi-quantum barrier sample suppresses the electron leakage through raised electron barrier， thus significantly improves the device performance.  
        关键词：AlGaN;deep ultraviolet light-emitting diodes;electron blocking layer   
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        发布时间：2024-07-25
      • “在有机发光二极管领域，研究者采用SiCzCz∶SiTrzCz2激基复合物主体材料，设计了高显色指数、低效率滚降的杂化TADF/磷光白光器件，为该领域提供了新的设计方案。”
        BIAN Haodong,LI Jiarui,ZHANG Chunfang,FENG Qi,HAO Yihong,CHEN Jinhui,XUE Rui,LI Dengfeng,LIU Yuan
        Vol. 45, Issue 7, Pages: 1163-1172(2024) DOI: 10.37188/CJL.20240066
        摘要：In organic light-emitting diodes （OLEDs）， the balance of carriers in the light-emitting layer and the broadening of the exciton distribution region are crucial for improving device efficiency. In this study， low-efficiency roll-off blue light-emitting devices based on thermally activated delayed fluorescence （TADF） materials DMAC-DPS and TDBA-SAF were fabricated by using exciplex host material SiCzCz∶SiTrzCz2. With the same host material， three-emitting-layer structure was constructed by introducing red phosphorescent emitter RD071 and green phosphorescent emitter Ir（ppy）2（acac）， realizing a high color rendering index. The exciplex host material SiCzCz∶SiTrzCz2 not only broadens the exciton distribution region and improves the charge balance， but also constructs a cascaded exciton energy transfer route by aligning the triplet energies of TADF/phosphorescent emitter materials. Subsequently， the white OLEDs （WOLEDs） effectively improve the exciton utilization and reduce the efficiency roll-off. By optimizing the device structure， WOLEDs achieved the highest external quantum efficiency， current efficiency and power efficiency of 23.0%， 45.9 cd·A-1 and 33.9 lm·W-1， respectively. Also， the device has a high color rendering index of 87， good color stability and low efficiency roll-off. This study provides a new design scheme for hybrid white light-emitting devices with high color rendering index and low efficiency roll-off.  
        关键词：organic light-emitting diodes;thermally activated delayed fluorescence;exciplex;charge balance;exciton transfer   
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        发布时间：2024-07-25
      • “Researchers have developed a high-performance self-driven ultraviolet photodetector using a NiO/BaTiO3/ITO p-i-n heterojunction structure, achieving a responsivity of 3.4×10^-5 A·W^-1 and a fast response speed of 0.3 s/0.4 s, offering a new strategy for improving the performance of photodetectors.”
        HONG Hanzhen,LIU Kewei,YANG Jialin,CHEN Xing,ZHU Yongxue,CHENG Zhen,LI Binghui,LIU Lei,SHEN Dezhen
        Vol. 45, Issue 7, Pages: 1173-1180(2024) DOI: 10.37188/CJL.20240118
        摘要：In recent years， self-driven ultraviolet （UV） photodetectors have become a central focus in both military and civilian fields as they can operate without any external power supply. As a wide bandgap ferroelectric material， Barium titanate （BaTiO3， BTO） possesses good ferroelectric， piezoelectric， and pyroelectric properties， which could generate intrinsic spontaneous polarization field to separate photogenerated carriers， resulting in a self-driven UV photoelectric detection. Till now， significant progress has been made on BTO-based self-driven photodetectors， however， the reported devices tended to exhibit low responsivity （10-8-10-7 A·W-1） except the use of high-quality single crystalline materials. In this work， we have fabricated a high-performance NiO/BTO/ITO p-i-n heterojunction structure self-driven UV photodetector using a low-cost RF sputtering technique. By coupling the ferroelectric depolarization field of BTO with the built-in field of p-i-n junction， the separation and migration of photogenerated carriers can be greatly promoted. Therefore， the responsivity at 255 nm of our device can reach to 3.4×10-5 A·W-1 under the poling-up state， which is much higher than that of reported UV photodetectors prepared from amorphous and ceramic BTO. In addition， our device exhibits a fast response speed of 0.3 s/0.4 s. The findings in this work provide a new strategy for improving the performance of BTO-based photodetectors.  
        关键词：BaTiO3;Ferroelectric effect;Self-driven;UV photodetector;p-i-n junction;depolarization field   
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      • “最新研究成功开发出一种新型高阶横模光纤激光器，通过对称耦合器和单模-少模-单模滤波器实现多波长、高纯度LP11模式激光输出，为光通信和光传感领域提供新方案。”
        LYU Xin,WANG Fan,MIAO Yunning,REN Wenhua,GUO Ying
        Vol. 45, Issue 7, Pages: 1181-1188(2024) DOI: 10.37188/CJL.20240077
        摘要：A multi-wavelength ring cavity high-order mode fiber laser based on a symmetrical fiber mode selective coupler （MSC） and single mode-few mode-single mode fiber filter was demonstrated and verified in this paper. The experimental result reveals that the proposed laser can operate stably in single-， dual-， triple- and quadruple-wavelength states with LP11 mode output， whose purities are 97.60%， 97.54%， 97.34% and 97.19%， respectively. The symmetrical fiber MSC is easy to be fabricated and stable， providing a new choice for the high-order mode fiber laser， which has potential applications in optical communications， optical sensing， etc.  
        关键词：Symmetrical fiber mode selective coupler;single mode-few mode-single mode fiber filter;Multi-wavelength;High-order mode   
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      • “在光电子集成领域，研究人员通过优化激光器外延P-InP掺杂和采用锥形波导结构，成功研制出低功耗高功率半导体激光器，为长距离主干网光网络和无人驾驶等应用提供研究基础。”
        XUE Zhengqun,CHI Bingkun,CHEN Yuping
        Vol. 45, Issue 7, Pages: 1189-1195(2024) DOI: 10.37188/CJL.20240088
        摘要：1.55 μm high power laser diodes are widely used in long-distance optical communication networks， unmanned driving， and other fields. The higher output power of the laser can effectively increase the transmission distance and improve the signal-to-noise ratio of the system. As the rapid development of photonic integration and co-packaged optics， high optical and electrical integration density requires lasers to have low power consumption performance. By optimizing the p-type profile and epi-growth of the laser epi-wafer， the series resistance of the lasers at room temperature was reduced from 3.2 Ω to 2.2 Ω， and the electrical power consumption was decreased from 510 mW to 430 mW， at a current of 300 mA. The resistance of the laser is better than the device prepared by the foreign company epi-wafer with the same structure. The taper waveguide was further adopted to increase the gain volume of the lasers. The results show that the taper structure increased the laser output power by more than 17%， while the electrical power of the device did not increase significantly. The highest photoelectric conversion efficiency of the device at room temperature and low current is close to 50%， which is comparable to the results reported in related studies. The far field results show that the lateral divergence angle of the laser is effectively reduced， and the beam quality of the device does not change significantly. The experimental results provide a research basis for low power consumption high-power semiconductor lasers for optoelectronic integrated applications.  
        关键词：1.55 μm;InP/InGaAsP;high power laser;p-type doping;taper waveguide   
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        Luminescence Industry and Technology Frontier

      • “最新研究揭示了高功率密度LED器件在光电性能上的突破，为半导体照明技术发展提供了新视角。”
        HUANG Linfeng,XIONG Chuanbing,TANG Yingwen,YUAN Hui,MA Yihao,YANG Xinyu
        Vol. 45, Issue 7, Pages: 1196-1210(2024) DOI: 10.37188/CJL.20240090
        摘要：High power density LED device can achieve many functions that is the traditional light sources and ordinary LED devices cann’t achieve， and it is pushing the LED lighting industry technology chain into a new level. In practical applications， the high power density LED needs to work at hundreds of watts and nearly 100 A current. The copper substrate area， solder tin and copper foil thickness will have a significant effect on the maximum light intensity， it is the most important indicator of this type LED. In this paper， we have welded the LEDs （300 W and 200 W， blue and white light） onto the thermoelectric separation copper substrates （Three diameters of the substrate： 32 mm， 25 mm， 20 mm. Three solder tin thicknesses between the LED and the substrate： 5 μm， 100 μm， 200 μm）. The I-L and I-V curves of the blue and white light LEDs have been tested， under different radiator temperatures （25 ℃， 50 ℃， 75 ℃ and 100 ℃， respectively）. The I-L and I-V characteristics of the blue light LED devices with a maximum electrical power of 150 W were also studied when the conductive copper foil thickness of the copper substrate was 70 μm and 140 μm， respectively. And its maximum optical output was studied. The research results indicate that the thickness of solder tin， the area of copper substrate， and the thickness of conductive copper foil all have significant effects on the maximum luminous intensity and operating voltage of the LEDs. The decrease of solder thickness and the increase of copper substrate area can significantly improve the maximum light intensity of the LEDs， the increase of maximum blue light optical power of the P110 and T90 LEDs can reach up to 16% and 19%， the increase of the maximum luminous flux of the white light LEDs is about 15%， respectively. When the thickness of the copper foil increases from 70 μm to 140 μm， the maximum optical power increase of P70 blue LED is 9.2% when the heat sink temperature is 25 ℃， 12.9% at 50 ℃ and 75 ℃， and 16.4% at 100 ℃.  
        关键词：high power density LED;thermoelectric separation copper substrate;soldering tin;conductive copper foil   
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