基于芴类寡聚物的蓝光聚合物光纤放大器

利用在POFs中掺杂一系列的芴类寡聚物,包括3-,5-（9,9-二辛基芴）和7-（9,9-二己基芴）,我们制作了工作在440～480nm的聚合物光纤（POF）放大器。纯寡聚芴类的增益性质证明增益系数量级在250dB／cm,放大自发辐射阈值在1～8μJ／cm^2,大大低于其他芴类增益介质。掺杂低聚物PMMA薄膜的光学和形态特性显示,低聚物在PMMA中高度孤立。利用适当的预制棒拉纤技术和掺杂寡聚芴类拉制的POFs的光学和增益性质测试表明。掺杂的2mmPOF增益值为0．07dB量级．寡聚芴类在POFs中高度孤立,为用于光学增益开关铺平了道路。     

多氟二苯乙炔类负性液晶化合物的合成

以烷基环己基酮、1,2-二氟苯为起始原料(或以2,3-二氟烷基苯为起始原料),采用正丁基锂低温下制得金属锂化试剂,再经过系列反应制得4-烷基环己基-2,3-二氟碘苯(或4-烷基-2,3-二氟碘苯),其与4-乙氧基-2,3-二氟苯乙炔发生Sonogashira偶联反应,合成出了3种2,3,2′,3′-四氟二苯乙炔类液晶化合物.进行了产品的结构标定以及参数测定,确定该类化合物有较大的光学各向异性(Δn)和负值较大的介电各向异性(Δε),并且具有较宽的相变温度范围,可以用于改善液晶材料的响应速度和驱动电压.     

两种新型芴类衍生物的三光子吸收特性研究

为了研究分子结构对三光子吸收的影响,合成了两种新型芴类衍生物,分别是2,7-二（2-4（甲氧基苯基）乙炔基）-9,9-二辛基-9H-芴（A）和2-溴-7-（2-（4-甲氧基苯基）乙炔基）-9,9-二辛基-9H-芴（B）,采用1064nm的Nd∶YAG激光器测试其三光子吸收截面的方法,得到了它们的三光子吸收截面分别高达（6.03±0.6）×10-76cm6·s2/photon2和（4.25±0.4）×10-76cm6·s2/photon2的结果,在高斯03软件下,用密度泛函方法对这两个分子进行了结构优化,并用含时密度泛函理论计算了它们的激发态能量和电子轨道。结果表明,分子内电荷转移方向对三光子吸收存在影响。     

蓝光共轭聚合物:聚(2,5-二己氧基)苯的合成及表征

以三氯甲烷为溶剂，采用三氯化铁氧化偶联反应合成了一种可溶性对称烷氧基取代聚对苯衍生物：聚（2，5-二己氧基）苯（DHO-PPP）。该聚合物可以很容易地通过溶液方式成膜，聚合物的结构通过红外光谱、核磁共振氢谱得到了确认，发现其中含有45％的聚（2，5-二己氧基-1，3）苯成分。在紫外-可见吸收光谱上，聚合物的三氯甲烷溶液的最大吸收峰位于351nm，与无取代的聚对苯相比红移了50nm。在300nm激发光下，聚合物的氯仿溶液发出了423．8nm的蓝光，表明材料是一种良好的蓝光材料。热重分析表明聚合物具有非常优异的热稳定性，在300℃时的质量损失只有2％。差示扫描量热法分析表明聚合物的玻璃化转变温度为102．34℃。X射线衍射分析表明，DHO-PPP是一种具有部分微晶结构的材料。     

樟脑型乙酰丙酮Pt配合物非线性光学性质及分子设计

在B3LYP/6-31++G(d,p)水平下(Pt原子采用LANL2DZ赝势基组),对几种樟脑型β-二酮环金属铂配合物的紫外-可见光谱和三阶非线性光学性质进行理论研究.结果表明,分子的电子跃迁性质属于金属到配体的跃迁(MLCT)、配体内跃迁(LC)和配体到配体的跃迁(LLCT)三种跃迁的混合.在苯环上引入-OC2H5分子的最强吸收峰和最低能量吸收峰均发生蓝移.在β-二酮环上引入苯基,同时在另一配体的苯环上引入氟代烷基可以增大非线性光学性质.在β-二酮环上引入吸电子基团-CF3使最低能量吸收峰红移,同时在另一配体苯环上引入烷氧基可以增大非线性光学性质.     

反铁电液晶正铁电相的介质分散

我们研究了反铁电液晶（R）-1-甲基庚基-4（4~-n-十二烷基氧联苯-4’碳烃氧基）-3-氟-苯甲酸盐铁电SmC相和正铁电SmCr相的介电特性。对于SmCr相,在实验的频率范围内判别出3种介质张驰。低频下具有高介质损耗的2种弛豫过程归因于锥角φ附近分子的方位变化。这些驰豫现象与温度和外加偏置电场间有函数关系。除了2个低频损耗过程外,还观察到一个额外的、强度较弱的损耗过程。     

1GHz,11ps超短光脉冲的波长变换实验

报道了采用国产的器件进行重复频率为1GHZ,脉冲最大半宽度为11ps的超短光脉冲基于半导体光放大器的交叉增益调制的波长变换实验。实验得到了以下几个结论：（1）变换信号光较初始光脉冲有较大的展宽,变换信号光的最大半宽度为初始信号光的最大半宽带的20倍;（2）变换信号的频谱宽度较原始信号光压窄;（3）变换信号的中心波长较原始信号的中心波长有轻微的红移;（4）变换信号的消光比比初始信号的消光比减小。     

2,3,4-三氟苯乙炔类液晶的合成

以2,3,4-三氟苯胺为原料,经桑德迈尔反应合成出2,3,4-三氟碘苯,2,3,4-三氟碘苯和2-甲基-3-丁炔-2-醇在四(三苯基膦)钯催化下合成4-(2,3,4-三氟苯)-2-甲基-3-丁炔-2-醇。4-(2,3,4-三氟苯)-2-甲基-3-丁炔-2-醇在氢氧化钾作用下生成2,3,4-三氟苯乙炔。2,3,4-三氟苯乙炔与6种碘代苯发生Sonogashira反应,合成出6种2,3,4-三氟二苯乙炔类液晶化合物。进行了产品结构标定以及参数的测定,确定了化合物具有较大的光学各向异性(Δn),较宽的相变温度范围。     

甲基氟远红外激光的斯塔克频移

本文对甲基氟(CH_3F)光泵远红外激光的斯塔克频移做了理论计算。指出用2.9×10~4～4.4×10~4伏/厘米的电场强度,有可能使甲基氟发射的远红外激光(496微米)与镁原子束的~3P_0→~3P_1跃迁共振,同时保证甲基氟的泵浦跃迁与 CO_2激光9P(20)线共振。预期可能的工作跃迁有四组:~QR(11,5,-11),~QQ(12,5,-11);~QR(11,6,-6),~QQ(12,6,-6);~QR(11,7,-3),~QQ(12,7,-3);~QR(11,8,0),~QQ(12,8,0)。     

980 nm激发下YLiF4:Er3+,Tm3+,Yb3+中的能量传递过程

利用水热法合成了YLiF4：Er^3＋，Tm^3＋．Yb^3＋，其中Er^3＋、Yb^3-和Tm^3＋的摩尔分数分别为2％、1．5％和2％。在这种共掺杂体系中，在980nm光的激发下，材料的上转换发光为白光，发光峰不仅分别位于665nm（651nm）、552nm（543）、484nm和450nm处，并在648nm处还观察到了一个发光峰，其中最强的发射为红光。蓝光主要来源于Tm^3＋的激发态^1G4到基态^3H6的跃迁，绿光来源于Er^3＋的^4S3/2和^2H11/2到基态^4I15／2的跃迁，红光既来源于Tm^3＋的^1G4→^3F4的跃迁，也来源于Er^3＋的^4F9/2→I15/2的跃迁。不同发射对应的激发光谱略有不同，当用不同波长光激发时，得到的发光不同，由此证明了Tm^3＋和Er^3＋之间存在能量传递，并且这种能量传递增强了红光的发射，降低了绿光的发射。     

Synthesis and optoelectronic properties of novel fluorene-bridged dinuclear cyclometalated iridium (III) complex with A–D–A framework in the single-emissive-layer WOLEDs

To explore the influence of push–pull chromophores on properties of emitter in organic light-emitting devices (OLEDs), an acceptor–donor–acceptor (A–D–A)-based dinuclear iridium (III) complex of (dfppy)₄Ir₂(dipic-FL) was synthesized via Suzuki coupling reaction, in which dfppy is 2-(2,4-difluorophenyl)pyridine and dipic-FL is 2,7-di(5-pyridyl-2-carboxyl)-9,9-dioctyl-9H-fluorene. An intense emission peak at about 480 nm resulting from the (dfppy)₂Ir(pic) chromophore and a weak long-wavelength emission band at 580–660 nm attributed to intramolecular charge transfer transition were exhibited for (dfppy)₄Ir₂(dipic-FL) in dichloromethane solution. But a remarkably hypsochromic photoluminescence profile with an intense characteristical emission peak at 422 nm was observed, which is attributed to the intraligand (IL) π–π^∗ excited states in its thin film. White emission with a maximum luminance of 1040 cd/m² and current efficiency of 1.2 cd/A was obtained in its single-emissive-layer (SEL) OLEDs with a configuration of ITO/PEDOT:PSS/(dfppy)₄Ir₂(dipic-FL) (10 wt%):TCTA/TPBi/LiF/Al. To our knowledge, this is one of the best examples in term of dinuclear iridium complex as single dopant in the high-performance white-emitting SEL-OLEDs.     

Highly efficient green and red OLEDs based on a new exciplex system with simple structures

To further simplify the devices based on the exciplex host, an electron-donor 4-[2-(9,9′-dimethylfluorene)]-triphenylamine (TPAF) with suitable highest occupied molecular orbital was used. Combined with an electron-acceptor 4,6-bis(3,5-di(pyridin-3-yl)phenyl)-2-methylpyrimidine (B3PYMPM) with appropriate lowest unoccupied molecular orbital, TPAF:B3PYMPM exhibits bluish-green exciplex emission and realizes ambipolar transporting property with a weight mixing ratio of 3:7. Owing to the appropriate characteristics of TPAF and B3PYMPM, OLEDs based on TPAF:B3PYMPM host were constructed with extremely simple device structures. All devices exhibit low turn-on voltages below 2.5 V and high maximum external quantum efficiencies of 20.1%, 19.2% and 5.4% for Ir(ppy)₂acac-, Ir(MDQ)₂acac-, and DCJTB-based devices. The results show that the feasibility of the TPAF:B3PYMPM exciplex system as the host in OLEDs, which possess both high performance and simplified device structure.     

White organic light-emitting diodes based on emission from DPVBi-doped 4,48-bis (2,28-diphenylvinyl)-1, 18-biphenyl

Organiclight-emitting diodes (OLEDs) have beenin-vestigated for many years on account of their highlumi-nance,low driven voltages ,wide visual range,flexiblesubstratesinflat-panel ,full color displays and backlightapplications .For high brightness and eff…     

High efficiency blue PhOLEDs using spiro-annulated triphenylamine/fluorene hybrids as host materials with high triplet energy,high HOMO level and high Tg

Two spiro-annulated triphenylamine/fluorene oligomers, namely 4′-(9,9′-spirobifluoren-4-yl)-10-phenyl-10H-spiro[acridine-9,9′-fluorene] (NSF-SF), and 4,4′-di(spiro(triphenylamine-9,9′-fluorene)-2-yl)-spiro(triphenylamine-9,9′-fluorene) (NSF-NSF), are designed and synthesized. Their thermal, electrochemical and photophysical properties were investigated. The introduction of spiro-annulated triphenylamine moieties assurances the high HOMO energy levels of NSF-NSF and NSF-SF at −5.31 eV and −5.33 eV, respectively, which accordingly facilitates the hole injection from nearby hole-transporting layer. Meanwhile, the perpendicular arrangement of the spiro-conformation and the full ortho-linkage effectively prevents the extension of the π-conjugation and consequently guarantees their high triplet energies of 2.83 eV. Phosphorescent organic light-emitting devices (PhOLEDs) with the configurations of ITO/MoO₃/TAPC/EML/TmPyPB/LiF/Al were fabricated by using the two compounds as host materials and bis[2-(4′,6′-difluorophenyl)pyridinato-N,C^2′]iridium(III) picolate (FIrpic) as the dopant. The turn-on voltage of the device B based on NSF-NSF was 2.8 V. Simultaneously, the device exhibited excellent performance with the maximum current efficiency of 41 cd A⁻¹, the maximum power efficiency of 42 lm W⁻¹ and the maximum external quantum efficiency (EQE) of 19.1%. At a high brightness of 1000 cd m⁻², the device remained EQE of 16.2% and the roll-off value of external quantum efficiency is 15%.     

Novel spiro-based host materials for application in blue and white phosphorescent organic light-emitting diodes

Two novel spiro-based host materials, namely 3-(9,9′-spirobi[fluoren]-6-yl)-9-phenyl-9H-carbazole (SF3Cz1) and 9-(3-(9,9′-spirobi[fluoren]-6-yl)phenyl)-9H-carbazole (SF3Cz2) were designed and synthesized. Due to the meta-linkage of spirobifluorene backbone, both SF3Cz1 and SF3Cz2 possess triplet energies over 2.70 eV, indicating they could serve as suitable hosts for blue and even white phosphorescent organic light-emitting diodes (PHOLEDs). The fabricated bis(4,6-(difluorophenyl)-pyridinato -N,C′)picolinate (FIrpic) based PHOLEDs hosted by SF3Cz1 and SF3Cz2 exhibited excellent performance with maximum external quantum efficiencies (EQEs) of 18.1% and 19.7%, respectively. Two-color warm white PHOLEDs fabricated by utilizing SF3Cz1 and SF3Cz2 as hosts also achieved high EQEs and low efficiency roll-offs. The results demonstrate that SF3Cz1 and SF3Cz2 are promising hosts for blue and white PHOLEDs.     

High morphology stability and ambipolar transporting host for use in blue phosphorescent single-layer organic light-emitting diodes

The authors report a small molecule host of 2,7-bis(diphenylphosphoryl)-9-[4-(N,N-diphenylamino)phenyl]-9-phenylfluorene (POAPF) doped with 8 wt% iridium(III)-bis[(4,6-difluorophenyl)pyridinato-N,C^2′]picolinate (FIrpic) for use in efficient and single-layer blue phosphorescent organic light-emitting diodes (PHOLEDs) exhibiting a maximum external quantum efficiency of ∼20.3% at brightness of 100 cd/m². The high performance of such single layer PHOLEDs is attributed to the POAPF host’s high morphological stability, suitable triplet energy level, and equal charge carrier mobilities of hole and electron to form the broad carrier recombination zone in the emitting layer, thus reducing the triplet-triplet annihilation and resulting in a slight efficiency roll off of 0.5% from the brightness of 1 and 1000 cd/m². This work also systematically investigated the arrangement of the POAPF:FIrpic recombination zone for optimizing the performance of the single layer PHOLED.     

Significance of irreversible formation of “electromer” in 1-bis[4-[N,N-di(4-tolyl)amino]phenyl]-cyclohexane layer associated with the stability of deep blue phosphorescent organic light emitting diodes

We demonstrate that injection of electrons in 1-bis[4-[N,N-di(4-tolyl)amino]phenyl]-cyclohexane (TAPC) layer irreversibly induces defect sites responsible for “electromer” emission. We also show that the defects alter the charge transporting properties of TAPC layer to influence the charge balance of iridium(III)[bis(4,6-difluorophenyl)pyridinato-N,C^2′]tetrakis(1-pyrazolyl)borate (FIr6) based deep blue phosphorescent organic light emitting diodes (PHOLED). The present investigation implies that deep-blue PHOLEDs should be carefully designed for the emission zone to be located far enough from the TAPC layer so as to avoid or minimize the emission from TAPC layer.     

WO3对掺铒碲酸盐玻璃的光谱性质的影响

为了满足光通信技术发展对光放大器材料的带宽要求,采用固相法制备了掺铒碲钨酸盐玻璃,研究了其光谱性质和热稳定性。用Judd-Ofelt理论计算了光谱的强度参量,根据McCumber理论计算了受激发射截面,其最大受激发射截面为1.85×10-20cm2,荧光半峰全宽最大值为104nm;用差热法分析了玻璃的热稳定性,析晶温度和转变温度之差最大值为131℃。结果表明,掺铒碲钨酸盐玻璃是一种良好的宽带放大器材料。     

NPB蓝色有机电致发光器件的性能优化研究

基于结构为ITO/NPB/BCP/Alq3/Mg:Ag的NPB(N,N’-bis(1-naphthyl)-N,N’-diphenyl-1,1’-biphenyl-4,4’-diamine)蓝色有机电致发光器件,利用Alq3的空穴阻挡能力及高的荧光效率优化了器件结构。具有不同厚度Alq3空穴阻挡层的器件性能测试结果表明,Alq3对器件发光亮度影响明显,选择适当的Alq3厚度可使得器件的发光亮度提高大约两倍。电致发光光谱测试结果表明,器件的发光基本来自NPB的蓝色发光,而Alq3扮演了辅助发光层的作用。