基于在聚合物中掺杂染料DCJTB的白色有机电致发光器件

将Alq₃和DCJTB作为掺杂物与基质PVK按照不同比例混合共溶,旋涂成膜,制备了PVK∶Alq₃∶DCJTB为发光层的结构为ITO/ PVK∶Alq₃∶DCJTB/ BCP/Alq₃/LiF/Al的器件,其中Alq₃和BCP分别用作电子传输层和空穴阻挡层,PVK用作蓝光发光层和空穴传输层。保持PVK和DCJTB的质量比为100∶1不变,改变PVK和 Alq₃的质量比,当PVK和Alq3的质量比为20∶1时,得到了效果较好的白光。器件在电压为14 V时,色坐标达到(0.33,0.36),在10～14 V范围内变化甚微。     

一种新型稀土配合物Eu(TTA)2(N-HPA)Phen的发光特性研究

合成了一种新的含有3个配体的稀土配合物Eu（TTA）2（N-HPA）Phen（TTA-噻吩甲酰基三氟丙酮，N—HPA=N-苯基邻氨基苯甲酸，phen=邻菲咯啉）。将稀土配合物作为掺杂物与基质PVK按照不同质量比混合共溶，旋涂成膜。通过荧光光谱，分析了薄膜的发光特性，并将其应用于有机电致发光。研究了PVK和Eu（TTA）2（N—HPA）Phen之间的能量传递，并且制备了发光层为PVK：Eu（TTA）2（N—HPA）Phen，结构为ITO／PVK：Eu（TrA）2（N—HPA）Phen／BCP／Alq3／Al的多层器件，发现改变PVK和稀土配合物的掺杂比，可以不同程度地抑制PVK的发光，最终得到纯的Eu^3＋的红色发光。实验结果证明，在PVK：Eu（TTA）2（N—HPA）Phen=5：1的质量比下，从PVK到稀土配合物之间存在充分的能量传递。     

ITO薄膜制备及RTA处理对发光器件特性的影响

采用射频反应磁控溅射生长铟锡氧化物(ITO)薄膜,通过X射线衍射(XRD)、透射光谱、四探针法及原子力显微镜(AFM)研究了生长条件、快速热退火(RTA)温度等对薄膜的晶化、透过率、电导率以及表面形貌的影响.以ITO/NPB/AlQ/Al结构的器件为例,讨论了不同的制备条件下ITO薄膜的表面效应对电致发光(EL)的影响,通过EL光谱表征发现,对ITO退火处理后,器件的相对发光强度明显增加,衰减速度减慢,器件的EL光谱有明显的变化.通过进一步分析认为,这是由于ITO薄膜表面的变化引起功函数的改变,从而引起电场重新分布造成的.     

Characteristics of pentacene organic thin film transistor with top gate and bottom contact

High performance pentacene organic thin film transistors (OTFT) were designed and fabricated using SiO₂ deposited by electron beam evaporation as gate dielectric material. Pentacene thin films were prepared on glass substrate with S--D electrode pattern made from ITO by means of thermal evaporation through self-organized process. The threshold voltage V_TH was --2.75± 0.1V in 0---50V range, and that subthreshold slopes were 0.42± 0.05V/dec. The field-effect mobility (μ_EF) of OTFT device increased with the increase of V_DS, but the μ_EF of OTFT device increased and then decreased with increased V_GS when V_DS was kept constant. When V_DS was --50V, on/off current ratio was 0.48× 10⁵ and subthreshold slope was 0.44V/dec. The μ_EF was 1.10cm²/(V.s), threshold voltage was --2.71V for the OTFT device.     

NPB/Alq3有机量子阱光电特性研究

利用热蒸发的方法制备了有机量子阱发光器件和Alq3单层发光器件,其中NPB(N,N′-Di-[(lnaphthalenyl)-N,N′-diphenyl]-(1,1′-biphenyl)-4,4′-diamine)作垒层,Alq3(Tris-(8-quinolinolato) aluminum)作阱层,量子阱结构类似于无机半导体的Ⅱ型量子阱结构.实验发现有机量子阱发光器件结构中存在垒层向阱层的F(o)rster无辐射共振能量转移,具有良好的电流-电压特性,光谱的窄化及蓝移,并且光谱的蓝移程度随电压的增大而逐渐增强.     

退火处理提高P3HT:PCBM聚合物太阳能电池光伏性能

利用旋转涂膜方法制备了以P3HT:PCBM为有源层的聚合物太阳能电池, 器件结构为ITO/PEDOT:PSS/P3HT:PCBM/Al(氧化铟锡导电玻璃/聚二氧乙基噻吩:聚对苯乙烯磺酸/聚三已基噻酚:富勒烯衍生物/铝),研究了退火温度对聚合物太阳能电池性能的影响. 实验发现: 聚合物薄膜经过120 °C退火10 min处理后, 开路电压(V_oc)达到0.64 V, 短路电流密度(J_sc)为10.25 mA·cm^-2, 填充因子(FF) 38.1%, 光电转换效率(PCE)达到2.00%. 为了讨论其内在机制, 对不同退火条件下聚合物薄膜进行了各种表征. 从紫外-可见吸收光谱中发现, 退火处理使P3HT在可见光范围内吸收加强且吸收峰展宽, 特别是在560和610 nm处的吸收强度明显增大; X射线衍射(XRD)结果表明, 120 °C退火后P3HT在(100)晶面上的衍射强度是未退火薄膜的2.8倍, 有利于光生载流子的输运; 原子力显微镜(AFM)研究结果表明, 退火显著增大了P3HT与PCBM的相分离程度, 提高了激子解离的几率; 傅里叶变换红外(FTIR)光谱验证了退火并没有引起聚合物材料物性的变化.     

两种磷光材料在聚合物掺杂体系中的发光特性研究

磷光材料由于可以利用电致激发所形成的单重态和三重态激子,因而可以得到接近100%的内量子效率。文章对常温下基于磷光材料Ir(ppy)₃及Ir(piq)₃掺杂PVK薄膜为发光层的器件的光学和电学特性进行了研究。光致发光的结果显示相同掺杂质量比下由PVK到Ir(piq)₃的能量传递比到Ir(ppy)₃更加困难。通过研究两种掺杂体系不同质量比的电致发光特性,可以认为这两种磷光器件的发光主要来自于磷光客体分子直接俘获载流子发光而非主体的能量传递。Ir(piq)₃掺杂体系对掺杂比例的依赖更为明显,从能级结构分析,认为是由于Ir(piq)₃的更低的HOMO及高的LUMO能级,而比Ir(ppy)₃具有更好的载流子俘获和传输特性。     

Synthesis and luminescent properties of ternary complex Eu(UVA)3Phen in nano-TiO2

By introducing 2-hydroxy-4-methoxy-benzophenone(UVA) and 1,10-phenanthroline(Phen) as the ligands, the ternary rare earth complex of Eu(UVA)3Phen is synthesized, and it is characterized by elemental analysis, mass spectra(MS) and infrared(IR) and ultraviolet(UV) spectroscopy. Results show that the Eu(III) in complex emits strong red luminescence when it is excited by UV light, and it has higher sensitized luminescent efficiency and longer lifetime. The organic-inorganic thin film of complex Eu(UVA)3Phen doped with nano-Ti O2 is prepared, and the nano-Ti O2 is used in the luminescence layer to change the luminescence property of Eu(UVA)3Phen. It is found that there is an efficient energy transfer process between ligands and metal ions. Moreover, in an indium tin oxide(ITO)/poly(N-vinylcar-bazole)(PVK)/Eu(UVA)3Phen/Al device, Eu3+ can be excited by intramolecular ligand-to-metal energy transfer process. The main peak of emission at 613 nm is attributed to 5D0→7F2 transition of the Eu3+, and this process results in the enhanced red emission.     

A simple encapsulation method for organic optoelectronic devices

The performances of organic optoelectronic devices, such as organic light emitting diodes and polymer solar cells,have rapidly improved in the past decade. The stability of an organic optoelectronic device has become a key problem for further development. In this paper, we report one simple encapsulation method for organic optoelectronic devices with a parafilm, based on ternary polymer solar cells(PSCs). The power conversion efficiencies(PCE) of PSCs with and without encapsulation decrease from 2.93% to 2.17% and from 2.87% to 1.16% after 168-hours of degradation under an ambient environment, respectively. The stability of PSCs could be enhanced by encapsulation with a parafilm. The encapsulation method is a competitive choice for organic optoelectronic devices, owing to its low cost and compatibility with flexible devices.     

ZnS:Er电致发光中SiO2与ZnS电子加速能力的比较

在分层优化结构和固态阴极射线发光中, 从电极注入的电子经电子加速层加速后获得更高能量成为过热电子, 过热电子碰撞激发发光中心引起发光, 其中SiO2 在提高过热电子的能量方面有非常重要的作用. ZnS作为电子加速层时, 也发现了固态阴极射线发光, 但其发光的亮度及稳定性都不及 SiO2作为电子加速层的器件. 通过比较 ZnS：Er在正弦交流电驱动下的正负半周内的亮度变化, 得出ZnS与SiO2的电子加速能力的相对大小. 实验结果表明： SiO2的电子加速能力是ZnS的2.18倍.