Preparation of Long-Lasting Phosphorescence (LLP) Glass-Ceramic Materials

Three kinds of glass-ceramics, i.e., Mn 2+ doped zinc borosilicate, Eu 2+, Dy 3+ co-doped strontium aluminoborate and Eu 2+, Nd 3+ co-doped calcium aluminoborate were prepared, whose phosphorescence emission band peaks at 525, 516 and 464 nm, respectively. In preparation of these glass-ceramics the base glasses were gained by heating the mixed starting materials at high temperature to get the transparent glasses; then those glasses were heat-treated and turned to opaque glass-ceramics. X-ray diffraction (XRD) shows that the crystallites are ZnSiO 4, SrAl 2O 4 and α-CaAl 2B 2O 7, respectively. It is a useful way to get new LLP materials by the method reported in this work that may be considered as “from glass to crystal”.

The Current Progress and Challenges of Carbonized Polymer Dot-Based Room-Temperature Phosphorescent Materials

Carbonized polymer dots(CPDs)as one type of carbon dots have attracted widespread attention in recent years.The proposal of the“shell–core”structure of CPDs leads to further thinking about the association between their special structures and luminescent properties.In recent years,great progress has been made in the field of CPD-based room-temperature phosphorescent materials.This review pays particular attention to how the special“core–shell”structure of CPDs influences the activation of roomtemperature phosphorescence(RTP).The strategies and vital factors to activate RTP for CPD-based materials in both solid state and water were reviewed in detail to elaborate on the effect of the special structure on RTP generation.Furthermore,some perspectives on the current challenges were also provided to guide the further development of CPD-based room-temperature phosphorescent materials.

Characterization of Y_2O_2S∶Eu ^(3+), Mg^(2+), Ti^(4+) Long-Lasting Phosphor Synthesized by Flux Method

Long-lasting phosphor Y2O2S ： Eu^3＋ , Mg^2＋ , Ti^4＋ was synthesized by a flux method and their luminescence properties were investigated. The result indicates that the unit cell parameter c is linearly increased with the increase of Eu2O3 content in Y2O2S： Eu^3＋ （0.01 ≤ x ≤0.10）. On the other hand, the change of unit cell parameter a is not linear dependence. In the Y2O2S： Eu^3 ＋ crystal structure, Eu^3＋ ions only replaced Y^3 ＋ ions＇ places in which it posited center position of c axis. With the increase of Eu2O3 content, the position of the strongest emission peak changed from 540 nm （5D1→^ 7F2 transition） to 626 nm （^5Do→^7TF2 transition）, and the maximum intensity was obtained when x = 0.09 in Y2O2S： Eu^3＋ （0.01 ≤x ≤0.10）. This is due to the environment of trivalent europium in the crystal structure of Y2O2S. Doping with Mg^2＋ or Ti^4＋. ions alone cannot get the good long-lasting afterglow effect, whereas co-doping with Mg^2 ＋ and Ti^4 ＋ ions and excited with 365 nm ultraviolet light, a strong thermoluminesence peak appeared, red and orange long-lasting phosphorescence （LLP） was also observed and the phosphorescence lasted nearly 3 h in the light perception of the dark-adapted human eye （0.32 mcd·m^-2）. Thus the LLP mechanism was analyzed.

Phosphorescence properties and energy transfer of red long-lasting phosphorescent(LLP) material β-Zn_3(PO_4)_2:Mn^(2+),Pr^(3+)

The red long-lasting phosphorescent （LLP） of β-Zn3（POa）2：Mn2＋,pr3＋ material was prepared through combustion and conventional solid-state sintering methods. The influence of Pr3＋ ions on luminescence and LLP of Mn2＋ in 13-Zn3（POa）2：Mn2＋,pr3＋ phosphor was systematically investigated. The phosphor presented a strong photoluminescence peak at 620 nm attributed to the 4T1g→ 6A1 g transition of Mn2＋ ions in octahedral coordination. Red LLP was observed in β-Zn3（PO4）2：Mn2＋,Pr3＋ phosphors with persistence time for more than 2 h. It was found that the long persistent phosphorescent performance of Mn2＋ such as brightness and duration was improved by the energy transfer from Pr3＋ to Mn2＋ when Pr3＋ ions as sensitizers were doped into matrix. The fact that the TL peak at low temperature was largely enhanced in Mn2＋, Pr3＋ codoped ^-Zn3（PO4）2 phosphor showed the significant increase of defect concentration with suitable depth. There existed two factors working together to be responsible for the enhancement of LLP performance in β-Zn3（PO4）2：Mn2＋,Pr3＋.

A silane-based host material with improved electron transport properties for phosphorescent OLEDs with high efficiency and low efficiency roll-off

A dibenzosilole-based host material was designed and characterized.The host material,9,9'-(5,5-diphenyl-5H-dibenzo[b,d]silole-2,8-diyl)bis(9H-carbazole)(SSiCz),was designed to enhance the electron transport properties and rigidity by coupling two phenyl units of the tetraphenyl silane of a strong hole transport type bis(4-(9Hcarbazol-9-yl)phenyl)diphenylsilane host.The device efficiency roll-off was improved considerably by balancing the carriers in the phosphorescent organic light-emitting diodes(PhOLEDs),and the driving voltage at high luminance was reduced.The red and green PhOLEDs exhibited high external quantum efficiencies(EQEs)of 23.8%and 24.9%,respectively,and a relieved efficiency roll-off.In addition,S-SiCz was used as an electron transport type host with a hole transport type3,3'-di(9H-carbazol-9-yl)-1,1'-biphenyl host.The maximum EQEs of the red and green PhOLEDs using the mixed host were 26.0%and 25.5%,respectively,and EQE roll-off values were 18%and 6%,respectively.Therefore,the planarization design strategy of the host is effective for better device performance.

Stimuli-Responsive Organic Ultralong Phosphorescent Materials with Complete Biodegradability for Sustainable Information Encryption

Constructingeco-friendlystimuli-responsivephosphorescence materials remains challenging and fascinating.Herein,we use natural cellulose as the rawmaterial to prepare pH-responsive room-temperature phosphorescent(RTP)materials with excellent biodegradability by introducing anionic structures.The introduction of a phenylcarboxylate substituent not only promotes intersystem crossing but also brings about electrostatic-attractive and strong hydrogenbonding interactions,which enhance the intermolecular chain interactions.Therefore,the obtained anionic cellulose derivatives containing phenylcarboxylate groups exhibit ultra-long RTP.More intriguingly,these cellulose-based phosphorescent materials have a distinctive pH-responsive behavior.Under acidic conditions,the carboxylate is converted into the carboxylic acid,resulting in phosphorescence quenching.This process is reversible.Moreover,the obtained cellulosebased phosphorescent materials have excellent processability and can be easily processed into various material forms,such as film,coating,and pattern,by using eco-friendly aqueous solution processing strategies.Such proof-of-concept biomass-based phosphorescent materials with unique pH-responsive behavior and excellent processability have a huge potential in information encryption,advanced anti-counterfeiting,and food monitoring.

取代基位置对2,4-二苯基吡啶类铱磷光配合物光物理性能的影响

铱磷光配合物具有高的发光效率、良好的热稳定性和发光颜色容易调节等优势,在有机发光二极管(OLED)、电化学发光池(LEC)、光催化、肿瘤诊断和传感器等领域有着重要的应用前景,是综合性能最优的电致磷光配合物。其颜色调控主要通过改变主配体和辅助配体的化学结构来实现,如通过改变配体的共轭程度、在配体上引入具有不同供/吸电子能力的取代基、在不同位置引入相同的取代基等方式可以实现发光颜色的调节,其中取代基的位置对铱磷光配合物光物理性能影响的研究较少。研究甲基处于不同取代位置对铱磷光配合物光物理性能的影响,以甲基处于2位和4位或3位和5位的2,4-二苯基吡啶为主配体、2,2,6,6-四甲基庚二酮为辅助配体,合成出2个新的铱磷光配合物(2,4-2Me-dppy)_(2)Ir(tmd)和(3,5-2Me-dppy)_(2)Ir(tmd)。通过元素分析、核磁共振谱和单晶X射线衍射等测试了配合物的组成和空间结构,两个配合物均呈稍微扭曲的八面体构型,空间群分别为C 12/c 1和P-1,晶系分别为单斜和三斜;通过热重分析研究了配合物的热稳定性,两个配合物均具有较好的热稳定性,热分解温度分别为307和318℃;通过紫外可见光谱和光致发光光谱研究了配合物的光物理性能,两个配合物在溶液中发射波长分别为545和572 nm,溶液中量子产率分别为70%和92%。进一步探讨了取代基位置对铱磷光配合物光物理性能的影响,研究发现:甲基所处的位置对2,4-二苯基吡啶类铱磷光配合物的发光颜色和发射波长有着显著的影响。与甲基处于2位和4位得到的铱磷光配合物相比,甲基处于3位和5位时得到的铱配合物的发射波长产生了明显的红移,为纯正的黄光发射,是一种潜在的黄光材料,并有望在OLED照明中得到应用。

酸皮基磷光型碳点的制备及防伪应用

以浸酸山羊皮为碳源、硼酸为硼源,采用热解法制备了磷光型碳点(P-CDs)。探讨了浸酸山羊皮含量、反应pH、反应温度和反应时间对P-CDs余辉时间的影响。采用有机元素分析仪、SEM、EDS、TEM、FTIR、XRD对样品进行了表征,并评价了P-CDs的防伪应用。结果表明,在浸酸山羊皮含量(以3 g硼酸为基准,下同)4.10%、反应pH为7、反应温度为225℃、反应时间为7.5 h的条件下,制备的P-CDs的余辉时间达到12s;该材料的最佳发射波长为520 nm,对应明亮的青绿色余辉。P-CDs平均粒径为4.42 nm,具有典型的石墨结构,硼原子成功地掺入到碳点中,形成了C—B、B—O等共轭链结构,稳定了三重激发态,延长了余辉时间。

新型吡啶甲酸类铱磷光材料的合成、晶体结构及性能

铱磷光材料由于发光效率高、热稳定性好、发光颜色易调控等优点,成为目前综合性能最优异的有机电致发光材料。Ir(C^N)2(L^X)型铱磷光配合物是最为重要的一类铱磷光发光材料,通过调控配体的化学结构,如引入供/吸电子基团、增大共轭程度等来达到改变发光颜色、发射波长和性能等目的。本工作从辅助配体着手,选用N^O型的吡啶甲酸衍生物为辅助配体,通过不同性质的基团对其结构进行调控;分别以3-三氟甲基-2-吡啶甲酸(Tricid)和异喹啉-1-甲酸(Qicid)为辅助配体,以2-(2,4-二氟苯基)-5-甲基吡啶(Medfppy)为主配体,设计合成出两种吡啶甲酸类铱磷光材料Ir1和Ir2。通过核磁共振谱、质谱和单晶X射线衍射等测试手段表征了它们的组成和化学结构,并确定了Ir1和Ir2的晶体结构,Ir1为单斜晶系,P2_(1)/c空间群;Ir2为三斜晶系,P-1空间群,均呈现出稍微扭曲的八面体构型;通过热重分析测试了材料的热稳定性,Ir1和Ir2的热分解温度分别为319℃和364℃;通过紫外-可见光谱和光致发光光谱研究了材料的光物理性能,Ir1和Ir2在二氯甲烷溶液中的最大发射波长分别为582 nm和607 nm;通过循环伏安法测试了材料的电化学性质,并计算得到材料的HOMO-LUMO能级。研究结果表明:与吡啶甲酸(Pic)上引入吸电子基团(-CF_(3))相比,增大共轭程度对铱磷光材料的发射波长作用程度较大;增大共轭程度不仅使配合物的最大发射波长产生了红移,还提高了材料的热稳定性,对设计新型的铱磷光材料具有一定的借鉴意义。

氮杂环苯基吡啶类铱配合物的合成及其器件性能

通过引入苯基吡啶,对2-甲基苯并呋喃并[2,3-b]吡啶-8-硼酸酯(Ⅱ)进行修饰,并对辅助配体进行部分氘代,同时对5-甲基-2-对甲苯基吡啶主配体的两个甲基进行全氘代,分别合成了2种铱配合物,双[5-甲基-2-(4-甲基苯基)吡啶基-N,C^(2)]{2-[7-(6-苯基吡啶-2-基)二苯并呋喃-4-基]-4-苯基吡啶}合铱(Ⅳ)和双{5-(甲基-d3)-2-[4-(甲基-d3)苯基]吡啶基-N,C^(2)}[2-{7-[6-(甲基-d3)吡啶-2-基]二苯并呋喃-4-基}-4-(苯基-d5)吡啶]合铱(Ⅳ-d_(20))。采用1HNMR、HRMS、元素分析仪对其结构进行了表征与确认。利用UV-Vis光谱、荧光发射光谱(PL)和循环伏安法对其光物理性质及能级结构进行了测试,以铱配合物Ⅳ和Ⅳ-d_(20)为客体制备了器件,并评价了其性能。结果表明,铱配合物Ⅳ和Ⅳ-d_(20)的光致发光光谱发射波长分别为546.9和548.0 nm,均是潜在的黄绿色磷光材料。铱配合物Ⅳ-d_(20)在电致发光下表现出更优异的器件性能。基于铱配合物(MMppy-d6)2Ir(MPPBFP-d8)的器件发射波长为552 nm,色坐标为(0.43,0.56),最大电流效率为97.49 cd/A,最大外量子效率为26.83%。

红光铂配合物在电致发光领域的研究进展

过渡金属配合物由于自身显著的自旋轨道耦合效应,可有效利用单线态激子和三线态激子发光,从而使理论内部发光量子效率达到100%,促进有机发光二极管在信息显示及固态照明等领域中的实际应用。其中,红光铂配合物对于高色纯度全彩平板显示以及白色照明的实现至关重要。综述了国内外红光铂配合物的分子设计、光发射特性及其在电致发光领域的研究进展,为进一步制备高效率、长寿命以及高色纯度的红色有机发光材料提供参考。

多色有机室温磷光材料设计策略的研究进展

多色有机室温磷光(Room Temperature Phosphorescent,RTP)材料因其发射寿命长、颜色可调、生物相容性好以及激发态性质可调控等独特的性质,在显示技术、防伪、数据加密以及传感等领域展现出巨大的应用潜力,近年来受到了研究者的广泛关注。然而,受限于有机材料的三重态激子固有的敏感性,其三重态发光性质的调控成为了一个重大挑战。因此,在有机体系中实现多色且稳定的RTP发射仍然是一项亟待解决的问题。本文旨在综述近年来在多色有机RTP材料设计方面所取得的进展,重点介绍了卤素效应、晶体工程、聚集体效应以及主客体掺杂策略。通过精心选择和设计磷光分子,结合分子内/分子间相互作用和聚集态调控,成功实现了多种颜色的RTP发射。希望本文能为多色RTP材料的合理设计提供一定的思路,并为多色RTP材料的各种前沿应用提供一定的指导。

Triphenyl Phosphine Oxide and Carbazole-based Polymer Host Materials for Green Phosphorescent Organic Light-emitting Diodes

Four novel polymers, poly（3,6-9-decyl-carbazole-alt-1,3-benzene） （PB13CZ）, poly（3,6-9-decyl-carbazole-alt- bis（4-phenyl） （phenyl） phosphine oxide） （PTPPO38CZ）, poly（3,6-9-decyl-carbazole-alt-2,4-phenyl（diphenyl） phosphine oxide） （PTPPO13CZ） and poly（3,6-9-decyl-carbazole-alt-bis（3-phenyl） （phenyl） phosphine oxide） （PTTPO27CZ） were synthesized, and their thermal, photophysical properties and device applications were further investigated to correlate the chemical structures with the photoelectric performance of bipolar host materials for phosphorescent organic light emitting diodes. All of them show high thermal stability as revealed by their high glass transition temperatures and thermal decomposition temperatures at 5% weight loss. These polymers have wide band gaps and relatively high triplet energy levels. As a result, the spin coating method was used to prepare the green phosphorescent organic light emitting diodes with polymers PTPPO38CZ, PTPPO13CZ and PTTPO27CZ as the typical host materials. The green device of polymer PTPPO38CZ as host material shows electroluminescent performance with maximum current efficiency of 2.16 cd.A-1, maximum external quantum efficiency of 0.7%, maximum brightness of 1475 cd.m-2 and reduced efficiency roll-off of 7.14% at 600 cd.m-2, which are much better than those of the same devices hosted by polymers PTTPO27CZ and PTPPO13CZ.

吸电子基团调控苯基喹啉类铱配合物的合成及光物理性能

以2,2,6,6-四甲基庚二酮(tmd)为辅助配体,2,4-二取代基苯基-4-甲基喹啉(2,4-2R-mpq)为主配体,在主配体中苯基的2位和4位同时引入氟(F)、甲氧基(MeO)或三氟甲基(CF_(3)),合成出3个铱磷光配合物(2,4-2R-mpq)_(2)Ir(tmd)(R=F(1)、MeO(2)、CF_(3)(3))。通过元素分析、核磁共振谱和单晶X射线衍射表征了配合物的组成和分子结构。通过紫外可见吸收光谱、光致发光光谱和理论计算对配合物的光物理性能进行了研究。结果表明:3个配合物的晶体均为三斜晶系,空间群均为P1,呈稍微扭曲的八面体构型。配合物1、2和3在溶液状态下的发射波长分别为570、582和604 nm,溶液中量子产率分别为96%、80%和80%。在主配体中苯基的2位和4位同时引入F或MeO,配合物电子云发生聚集,而引入CF_(3),配合物的电子云分散。与配合物3相比,配合物1和2的发射波长发生了显著的蓝移。

Silafluorene moieties as promising building blocks for constructing wide-energy-gap host materials of blue phosphorescent organic light-emitting devices

In this article, we reported the synthesis and characterization of a novel silafluorene-based host material, 1,3-bis(5-methyl-5Hdibenzo[b,d]silol-5-yl)benzene(Me-DBSi B), for blue phosphorescent organic light-emitting devices(PHOLEDs). The MeDBSi B was constructed by linking 9-methyl-9-silafluorene units to the phenyl framework through the sp3-hybridized silica atom to maintain high singlet and triplet energy, as well as to enhance thermal and photo-stability. The calculated result shows that the phenyl core does not contribute to both the highest occupied molecular orbital and lowest unoccupied molecular orbital. Wide optical energy gap of 4.1 e V was achieved. When the Me-DBSi B was used as the host and iridium(III) bis[(4,6-difluorophenyl)pyridinato-N,C2′]picolate(Firpic) as the guest, a maximum current efficiency was 14.8 cd/A, lower than the counterpart of 1,3-bis(9-carbazolyl)benzene(28 cd/A). The unbalanced barrier for electron and hole injection to host layer may be responsible for low efficiency. Even so, our results show that silafluorene moieties are promising building blocks for constructing wide-energy-gap host materials.

铂配合物磷光材料在OLED中的应用研究进展

有机发光二极管(OLED)开发和商业化的一项关键突破是将磷光材料用作发光材料,与荧光材料相比,磷光材料的内部量子效率提高了3倍。在所有磷光材料中,方形平面铂(Ⅱ)配合物由于高的结构刚性而表现出磷光量子产率高、磷光寿命短以及化学和热稳定性高等优点,这对于实现具有长使用寿命的OLED至关重要。另一方面,铂(Ⅱ)配合物由于其平面配位几何形状,可以轻松构建二齿、三齿或四齿配体,从而可显著调控铂(Ⅱ)配合物的光物理性质。除此之外,含多个Pt中心可以进一步增强分子的自旋轨道耦合作用从而增强其磷光发射。基于以上考虑,该文对含二齿、三齿和四齿配体的单核及多核铂(Ⅱ)配合物在OLED发光材料中的应用进行了总结,并讨论了配体结构对器件性能的影响。最后,对铂(Ⅱ)配合物材料的研究难点进行了分析,对其未来的发展趋势进行了展望。

基于有机发光材料的高性能PeLEDs的研究进展(特邀)

近年来,金属卤化物钙钛矿发光材料由于具有优异的光电性能,被广泛地应用于金属卤化物钙钛矿发光二极管(Perovskite light-emitting diodes,PeLEDs),被视作下一代显示和照明领域的发光光源。激子利用率是影响PeLEDs效率的关键因素之一,研究者采用各种各样的方法将激子限制在钙钛矿发光层中,对激子能量回收利用以提高激子的利用率。文中将概述通过添加剂辅助法、器件界面工程和结构优化法,将传统荧光材料、磷光材料、热激活延迟荧光材料引入器件,改善绿光和蓝光PeLEDs的光电性能方面所做的尝试。并简要地介绍激子限制作用的原理,以及不同类型的发光材料引入PeLEDs中激子的能量转移机理和器件光电性能提升的物理机理。

道路标线视认性提升技术研究进展

文中就近年来国内外关于提升道路标线视认性的研究进行了回顾和总结,梳理了目前常用的两类道路标线材料,介绍了不同标线材料产生视认性的原理,综合评价了不同标线材料的实际性能及其优缺点.从原材料与施工工艺的角度阐述了影响道路标线视认性的主要因素及相关的改进措施,通过总结道路标线材料的发展趋势,指出发展环保型高性能冷塑性标线材料、自发光LED标线材料和以铕、镝掺杂铝酸锶(SrAl_(2)O_(4):Eu^(2+),Dy^(3+))为代表的新型蓄能自发光型材料将是未来的发展方向.

有机小分子荧光材料的前生今世

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