室温下磁场对基于Alq3的有机电致发光器件的影响

制备了ITO/NPB/LiF/Alq₃/LiF/Al的器件,测量了该组器件效率和亮度的磁效应.结果表明,在50 mT磁场中,当LiF缓冲层厚度为0.8 nm时,器件的效率最大增加了12.4%,磁致亮度最大变化率17%.同时,制备的磷光器件ITO/NPB/LiF/CBP:6 wt% Ir(ppy)₃/BCP/Alq₃/ LiF/Al,在50mT磁场作用下,当LiF缓冲层的厚度为0.8 nm时,器件的效率最大增加12.1%.在Alq_{3 关键词： 有机发光 磁场 效率 磁致亮度}     

磁场作用下的有机电致发光

分别制备了荧光器件ITO/NPB/Alq₃/LiF/Al和磷光器件ITO/NPB /CBP: Ir（ppy）₃/BCP/Alq₃/LiF/Al, 测试了50 mT磁场作用下器件的I-V和L-V特性. 与零磁场相比荧光器件和磷光器件的效率分别增加了44%和7%. 从有机电致发光的机制出发对该现象进行了解释, 认为外加磁场可以使三重态激子发生塞曼分裂, 进而在荧光器件中引起了三重态激子T     

LiF插层对有机发光二极管磁场效应的调控

制备了有LiF插层的有机发光二极管,以八羟基喹啉铝（Alq₃）作为电子传输层,N, N′-二苯基-N, N′-二(1-萘基)-1,1′-联苯-4,4′-二胺（NPB）作为空穴传输层.通过改变Alq₃与NPB间LiF插层的厚度,研究了不同温度下器件的光电特性及电致发光的磁场效应.测量结果表明:LiF插层可以影响器件内部载流子的输运和激发态的形成.较厚的插层阻碍了空穴的传输,使器件的电流效率变低.但实验中发现, 关键词： LiF插层结构 磁场效应 三重态激子     

非掺杂型高效绿色磷光有机电致发光器件

在空穴传输层TCTA与电子传输层TPBi之间引入磷光染料Ir(ppy)3超薄发光层,制备了结构为ITO/MoO_3(2 nm)/NPB(40 nm)/TCTA(10 nm)/Ir(ppy)3(xnm)/TPBi(40 nm)/LiF(1 nm)/Al(80 nm)的非掺杂磷光有机电致发光器件。通过调控非掺杂发光层的厚度,详细研究了Ir(ppy)3层厚度对器件性能的影响。实验结果表明,当非掺杂发光层厚度为0.2 nm时,器件的性能最好,器件的亮度、效率和外量子效率分别达到26 350 cd·m~(-2)、42.9 cd·A~(-1)和12.9%。研究结果表明,采用超薄的非掺杂发光层可以简化器件结构和制备工艺,获得高效率的OLED器件。     

Alq_3发光层厚度对有机电致发光器件性能的影响

文章以MoO3为空穴注入层,NPB为空穴传输层,改变发光/电子传输层Alq3的厚度,考察了器件电学和光学性能的变化。结果表明,随着Alq3层增加厚度,器件的电流逐步减小,由此获得Alq3薄膜的电场分布情况;器件发光光谱有少量红移,但长波端明显展宽,短波端强度下降。该文拟合了器件电致发光谱,与实验曲线吻合较好。同时拟合结果也表明,干涉效应主要影响光谱在长波端的强度分布,发光区域分布决定光谱在短波端的强度分布。     

磁场对基于Co铁磁薄膜的有机发光器件效率和电流的影响

制备结构为ITO/Co/NPB/Alq₃/LiF/Al的有机发光器件,测量了室温下磁场对器件发光效率和电流的影响.发现磁场强度小于80 mT时,器件发光效率随磁场强度的增加而增大,最大为18.8%,随磁场强度的继续增加发光效率的增强趋于饱和.效率的增加是Co的自旋极化的注入和磁场效应共同作用的结果,其中自旋极化注入起主要作用.在磁场强度小于60 mT时电流随磁场增强而增加,最大为6.9%,随磁场强度的进一步增加电流的增加有所减弱.产生这种现象的原因可归结为磁场相关的单线态极化子对的解 关键词： 有机电致发光 自旋极化 磁场效应     

Diamine的光、电性质及其在有机薄膜电致发光器件中的应用

合成了芳香族二胺类衍生物(diamine),测定了它的光、电性质.制备了diamine作为空穴传输层的二层结构有机薄膜电致发光器件,使器件的发光亮度相对单层器件有了很大的提高.并用不同区域掺杂的方法,探讨了电致发光机理.分析、讨论了激子的形成和复合区域,较好地解释了单、双层器件的不同的电流电压关系和不同的亮度电压关系.从激子的扩散方程出发,对双层掺杂器件的发光强度比数据进行了拟合,确证了激子的扩散模式.     

有机电致发光材料与器件

简要介绍了有机电致发光器件的结构、电致发光机理、可用作电致发光材料的种类以及存在的一些问题，简述了电致发光材料及器件的研究现状及对未来的展望。     

有机薄膜材料的电致发光

有机薄膜材料的电致发光具有低压直流驱动、高亮度、高效率、多色、可制成大面积等优点 ,近几年来取得突破性的进展引起了越来越多的关注和兴趣。本文主要介绍了它的发展历程、器件的结构与材料、发光的基本原理等     

磁场和量子点尺寸对激子性质的影响

在In_0.6Ga_0.4As/GaAs量子点中,采用一维等效势模型和有限差分法理论计算了激子态的性质,得到了激子跃迁能和束缚能随磁场、横向束缚强度以及量子点尺寸的变化关系.结果表明:加入磁场后,Zeeman效应使得激子的能级简并度解除,激子的基态跃迁能与实验符合得很好;横向束缚强度或磁场强度的增加使得激子的束缚增强;量子点的尺寸对激子的束缚产生重要的影响;通过电子-空穴间平均距离以及激子体系波函数分布图像分析了其产生的物理机制.     

Magnetic field effects on excited states,charge transport,and electrical polarization in organic semiconductors in spin and orbital regimes

Magnetic field can influence photoluminescence, electroluminescence, photocurrent, injection current, and dielectric constant in organic materials, organic–inorganic hybrids, and nanoparticles at room temperature by re-distributing spin populations, generating emerging phenomena including magneto-photoluminescence, magneto-electroluminescence, magneto-photocurrent, magneto-electrical current, and magneto-dielectrics. These so-called intrinsic magnetic field effects (MFEs) can be observed in linear and non-linear regimes under one-photon and two-photon excitations in both low- and high-orbital materials. On the other hand, spin injection can be realized to influence spin-dependent excited states and electrical conduction via organic/ferromagnetic hybrid interface, leading to extrinsic MFEs. In last decades, MFEs have been serving as a unique experimental tool to reveal spin-dependent processes in excited states, electrical transport, and polarization in light-emitting diodes, solar cells, memories, field-effect transistors, and lasing devices. Very recently, they provide critical understanding on the operating mechanisms in advanced organic optoelectronic materials such as thermally activated delayed fluorescence light-emitting materials, non-fullerene photovoltaic bulk-heterojunctions, and organic–inorganic hybrid perovskites. While MFEs were initially realized by operating spin states in organic semiconducting materials with delocalized π electrons under negligible orbital momentum, recent studies indicate that MFEs can also be achieved under strong orbital momentum and Rashba effect in light emission, photovoltaics, and dielectric polarization. The transition of MFEs from the spin regime to the orbital regime creates new opportunities to versatilely control light-emitting, photovoltaic, lasing, and dielectric properties by using long-range Coulomb and short-range spin–spin interactions between orbitals. This article reviews recent progress on MFEs with the focus on elucidating fundamental mechanisms to control optical, electrical, optoelectronic, and polarization behaviors via spin-dependent excited states, electrical transport, and dielectric polarization. In this article both representative experimental results and mainstream theoretical models are presented to understand MFEs in the spin and orbital regimes for organic materials, nanoparticles, and organic–inorganic hybrids under linear and non-linear excitation regimes with emphasis on underlying spin-dependent processes.     

电致发光色纯性增强的硅基有机微腔

报道了硅基有机微腔的电致发光（EL）.该微腔由上半透明金属膜、中心有源多层膜和多孔硅分布Bragg反射镜（PS DBR）组成.半透明金属膜由Ag（２０nm）构成，充当发光器件的负电极和微腔的上反射镜.有源多层膜由Al (1 nm) / LiF(05 nm) /Alq3/Alq3:DCJTB/NPB/CuPc/ITO/SiO2组成，其中的Al/LiF为电子注入层，ITO为正电极，SiO2为使正、负电极电隔离的介质层.该PS DBR是采用设备简单、成本低廉且非常省时的电化学腐蚀法用单晶Si来制备的；该PS 关键词： 电化学腐蚀 电致发光 窄峰发射 硅基有机微腔     

高场作用下有机双层器件的场致复合发光

以在高场作用下载流子对三角势垒的Fowler Nordheim隧穿理论为基础 ,建立了双层有机电致发光器件载流子的输运与复合发光模型。求出了稳态下电荷载流子的复合发光与电压和界面势垒的函数关系式 ,计算并讨论了所加电压和阳极区与阴极区厚度之比 (Lh/Le)对复合发光的影响。该理论模型很好地解释了电场对复合区域的调制作用。     

ZnO纳米棒的低温溶液法制备、光电特性研究及其在有机/无机复合电致发光中的应用

利用水热法制备了垂直于衬底的定向生长的ZnO纳米棒,利用扫描电子显微镜及光致发光的方法对其形貌及光学特性进行了表征,利用场发射性能测试装置对ZnO纳米棒的场发射性能进行了测试.结果表明:利用水热法在较低的温度(95 ℃) 下生长了具有较好形貌和结构的ZnO纳米棒,并表现出了较好的场发射特性,当电流密度为1 μA/cm²时,开启电场是2.8 V/μm,当电场为6.4 V/μm时,电流密度可以达到0.67 mA/cm²,场增强因子为3360.稳定性测试表明,在5 h内,4.5 V/μm的电场下,其波动不超过25%.将制备的ZnO纳米棒应用到有机/无机电致发光中,其中ZnO纳米棒为电子传输层,m-MTDATA(4,4',4″-tris{N,(3-methylphenyl)-N-phenylamino}-triphenylamine) 为空穴传输层,得到了ZnO的342 nm的紫外电致发光,此发光较ZnO纳米棒光致发光的紫外发射有约40 nm的蓝移. 关键词： ZnO纳米棒 场发射 水热法 有机/无机复合电致发光     

Magnetic field effects in proteins

ABSTRACT

Many animals can sense the geomagnetic field, which appears to aid in behaviours such as migration. The influence of man-made magnetic fields on biology, however, is potentially more sinister, with adverse health effects being claimed from exposure to fields from mobile phones or high voltage power lines. Do these phenomena have a common, biophysical origin, and is it even plausible that such weak fields can profoundly impact noisy biological systems? Radical pair intermediates are widespread in protein reaction mechanisms, and the radical pair mechanism has risen to prominence as perhaps the most plausible means by which even very weak fields might impact biology. In this New Views article, I will discuss the literature over the past 40 years that has investigated the topic of magnetic field effects in proteins. The lack of reproducible results has cast a shadow over the area. However, magnetic field and spin effects have proven to be useful mechanistic tools for radical mechanism in biology. Moreover, if a magnetic effect on a radical pair mechanism in a protein were to influence a biological system, the conditions necessary for it to do so appear increasing unlikely to have come about by chance.     

SiO2/C9-PPV异质结中类阴极射线发光及有机电致发光的交互增强

用夹在两层SiO2之间的发光聚合物C9-PPV作成器件，在交流电激发下得到了超出有机电致发光黄绿色发光的蓝色发光.通过对器件光学特性的研究，发现这种发光源于SiO2中加速电子直接碰撞激发有机发光层而引起的类阴极射线发光.使用非对称结构，得到了类阴极射线发光与有机电致发光相互增强的混合发光. 关键词： 混合发光 类阴极射线发光 有机电致发光