一种具有室温磷光的碳量子点基复合材料

碳量子点的荧光性能已被广泛研究,但很少有人关注碳量子点的磷光现象和机理。通过静电自组装法将带负电荷的碳量子点作为发光中心和核心先后吸引活性Ba2+和活性SO42-,使碳量子点固定在所生成的BaSO4基质中,形成一种新型的同时具有优异室温磷光和荧光的碳量子点基复合材料（记作CQDs@BaSO4）。该材料在激发波长为365nm下显示出的长磷光寿命为281ms,平均寿命为251ms,并且在水和酸碱溶液中都具有稳定的室温磷光发射现象。同时研究了磷光现象的机理,该材料室温磷光归因于碳量子点表面的其表面所含芳香羰基化合物的三重态和BaSO4分子有效的刚化这些芳香族羰基基团,从而抑制非辐射钝化途径产生室温磷光。基于该材料磷光性能的优点,成功将其制成防伪印泥材料,探讨其在磷光防伪上的应用。国家自然科学基金国际(地区)合作与交流资助项目(51561135015);国家自然科学基金面上资助项目(51572232

Advance in Red-emitting Mn⁴⁺-activated Oxyfluoride Phosphors

稳定可靠的高光子能量发光(620~650 nm)红光荧光粉, 对于构建低色温、高显指荧光粉转换型白光发光二极管(WLED)至关重要。Mn⁴⁺激活红光荧光粉是当前 WLED 用荧光粉研究热点之一。本文介绍了 Mn⁴⁺离子的能级跃迁与光致发光特性, 详细叙述了目前所报道的七种 Mn⁴⁺激活含 d⁰/d¹⁰/s⁰离子氧氟化物系列红色荧光粉(如Na₂WO₂F₄:Mn⁴⁺等)的制备方法、晶体结构及其发光特性。目前⁴⁺在氧氟化物结构中得到强 R 线(零声子线)发光的情况少, 微观配位体仍是[MnF₆]或[MnO₆], 其化学稳定性和量子效率研究也很缺乏。最后对 Mn⁴⁺激活氧氟化物红光荧光粉的研究进行了展望。The stable and reliable red phosphor with high-photon energy emission (620–650 nm) is critical for the fabrication of the phosphor-converted white light-emitting diode (WLED) with low correlated color temperature and high color rendering index. Mn⁴⁺-activated phosphor is an emerging kind of red-emitting phosphor for WLED. Herein, the energy levels transition and photoluminescence characteristics of the Mn⁴⁺ ion were introduced; then, the preparation, crystal structure and luminescent properties of as-far reported seven kinds of Mn⁴⁺-doped oxyfluoride red phosphors (such as Na₂WO₂F₄:Mn⁴⁺) containing d⁰/d¹⁰ or s⁰ cations were reviewed. Currently, only in quite rare case of oxyfluoride, Mn⁴⁺ was found to exhibit strong R-line emission, with local coordination remaining as either [MnF₆] or [MnO₆]. The studies on the chemical stability and quantum efficiency of Mn⁴⁺ -doped oxyfluoride phosphors are still insufficient. Finally, we prospected the future development of Mn⁴⁺-doped oxyfluoride phosphor

Ca1_xLixAl1_xSi1+xN3：Eu2+ solid solutions as broadband,color-tunable and thermally robust red phosphors for superior color rendition white light-emitting diodes

日前，我院解荣军教授及其合作者在半导体照明用稀土掺杂氮化物发光材料研究上取得突破性进展。稀土发光材料是半导体照明技术中最为关键的核心材料之一，决定了半导体照明器件的发光效率、显色指数、色温和可靠性等重要性能。解荣军教授及其合作者在长期研究氮化物发光材料及半导体照明器件的工作基础上，巧妙地通过发光材料的晶体结构局域调控和能带工程设计，研究和开发了具有宽谱发射、光谱可控的高可靠性氮化物固溶体红色发光材料，成功解决了半导体照明技术中的重要科学问题和关键技术难题。该论文的第一作者为中国计量大学光学与电子技术学院的王乐副教授，解荣军和王乐为共同通讯作者，厦门大学为第一通讯单位。合作单位还有日本国立材料研究所、重庆邮电大学和台湾大学。由于文章具有创新性和重要性，被选为当期封面文章。【Abstract】Color rendition, luminous efficacy and reliability are three key technical parameters for white light-emitting diodes (wLEDs) that are dominantly determined by down-conversion phosphors. However, there is usually an inevitable trade-off between color rendition and luminescence efficacy because the spectrum of red phosphor (that is, spectral broadness and position) cannot satisfy them simultaneously. In this work, we report a very promising red phosphor that can minimize the aforementioned trade-off via structure and band-gap engineering, achieved by introducing isostructural LiSi2N3 into CaAlSiN3:Eu2+. The solid solution phosphors show both substantial spectra broadening (88→117 nm) and blueshift (652→642 nm), along with a significant improvement in thermal quenching (only a 6% reduction at 150 °C), which are strongly associated with electronic and crystal structure evolutions. The broadband and robust red phosphor thus enables fabrication of super-high color rendering wLEDs (Ra=95 and R9=96) concurrently with the maintenance of a high-luminous efficacy (101 lm W−1), validating its superiority in high-performance solid state lightings over currently used red phosphors.We are grateful for the financial support from the JSPS KAKENHI (No. 23560811), the National Natural Science Foundation of China (Nos. 51272259, 61575182, 5157223 and 51561135015), the Natural Science Foundation of Zhejiang Province (No. Y16F050012) and the Taiwan Science and Technology Authority (No. ‘MOST’ 104-2113-M-002-012-MY3 and No. 104-2119-M-002-027-MY3)

Overview of(oxy) nitride phosphors

氮(氧)化物荧光粉是半导体照明技术中至关重要的原料之一。对氮(氧)化物荧光粉近期的研究成果进行了总结,并展望了其发展方向。( Oxy) nitride phosphors were one of the most important luminescent materials for solid state lighting technologies.In this paper,presented an overview on the recent trends and developments in rare earth-activated( oxy) nitride phosphors.国家自然科学基金资助项目(51272259

Fabrication of W–Cu functionally graded material by spark plasma sintering method

Three-layered(W–25Cu/W–50Cu/W–75Cu,volumefraction)W/Cufunctionallygradedmaterial(FGM)was synthesizedbysparkplasmasintering(SPS)atdifferenttemperaturesfor5minunderaloadof40MPa.The in？uencesofdifferentsinteringprocessesonrelativedensity,hardness,thermalconductivityandmicrostructure atvariouslayersofsinteredsampleswereinvestigated.Theexperimentalresultsindicatedthatthegraded structureofthecompositecouldbewelldensi？edaftertheSPSprocess.Therelativedensityincreasedwith theincrementofsinteringtemperatureanditwasupto96.53%assinteredat1050°C.Inaddition,thethermal conductivityreached140W/m·Katroomtemperatureand151W/m·Kat800°C,whichcouldbeascribedto thespeci？cstructurethatWparticlesenwrappedbynet-likeCu.AndtheVickershardnesswasconverted from4.11to4.68GPa

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以番茄品种"安娜"、"保罗塔"、"倍盈"为试材,研究了脱落酸和寡糖对番茄产量、抗病性及经济效益的影响。结果表明:施用脱落酸和寡糖后,3个番茄品种均表现增产,平均增产率为21.6%,其中"安娜"增产最多;施用脱落酸和寡糖后使番茄果实增大,品种"保罗塔"效果最明显,其次是"安娜",最后是"倍盈";"安娜"的果实横径最大,其次是"保罗塔";供试3个品种的果实重量增加明显;喷施脱落酸的大棚发病率较低