混合发光层有机电致发光器件中的多重成分发射  

Multiple Emissions in Organic Electroluminescent Device Using a Mixed Layer as an Emitter

作　　者：朱文清[1] 吴有智[1] 郑新友[1] 蒋雪茵[1] 张志林[1] 孙润光[1] 许少鸿[1] 

机构地区：[1]上海大学嘉定校区材料系,上海201800

出　　处：《光谱学与光谱分析》2005年第4期509-511,共3页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金 (60 0 0 770 2 0 ) ;国家自然科学基金重点项目 (90 2 0 1 0 34) ;"863"项目 (2 0 0 1AA31 30 70 ) ;上海市光科技专项(0 1 2 2 61 0 55);上海市教委自然科学项目 (0 3AK2 6)资助

摘　　要：以等摩尔空穴传输材料TPD和电子传输材料PBD组成结构为ITO/TPD/TPD∶PBD/PBD/Al的混合物发光层有机电致发光(EL)器件,观察到了相对于组成材料的荧光光谱红移的宽发射带。通过比较EL光谱,光致发光光谱及EL光谱分解,表明电致发光中同时包含单体发射、激基复合物和电荷对复合物的发射。激基复合物为TPD的激发态TPD 与PBD的基态相互作用形成TPD PBD类型的复合物,电荷对复合物是带电荷的空穴传输分子(D+ )的空穴和电子传输分子(A-)的电子交叉复合而形成的(D+ -A-) 复合物。各激发态在电场作用下呈现不同的形成机理和复合过程,并且单体发射和激发态复合物的比例随电场而变化,导致发射光谱随电场增强而蓝移。该器件的最高亮度和最大外部量子效率分别为2 4 0cd·(cm2 ) -1和0 .4 9%。有机固态界面激基复合物或电荷对复合物的发射常出现宽的红移发射带,是调节发光颜色的有效手段。A organic electroluminescent device has been fabricated by using a mixed layre as an emitter. The configuration of the device is ITO/TPD/TPD: PBD(equimole)/PBD/Al, in which TPD (N, N'-diphenyl-N, N'-bis(3-methylphenyl)-1, 1'-biphenyl-4, 4'-diamine) and PBD(2-(4'-biphenyl)-5-(4'-tert-butylphenyl)-1, 3, 4-oxadiazole) are used as hole transport material and electron transport material, respectively. Broad and red-shifted electroluminescent spectra related to the fluorescence of constituent materials were observed. It is suggested that the monomer, exciplex and electroplex emissions are simultaneously involved in EL spectra by comparison of the EL with the PL spectra and decomposition of the EL spectrum. The type of exciplex is the interaction between the excited state TPD(TPD*) and PBD in the ground state, and the type of electroplex is a (D+ - A(-)) * complex by cross-recombination of hole on the charged hole transport molecule(D+) and electron on the charged electron transport molecule(A(-)). All types of excited states show different formation mechanisms and recombination processes under electric field. The change of emission strengths from monomer and excited complexes lead to a blue-shift of the emissive spectra with an increasing electric field. The maximum luminance and external quantum efficiency of this device are 240 cd (.) (cm(2))(-1) and 0.49%, respectively. The emissions from exciplex or electroplex fort-nation. at the organic solid interface generally present a broad and red-shifted emissive band, providing an effective method for tuning of emission color in organic electroluminescent devices.

关 键 词：有机电致发光器件 发光层 激基复合物 成分 多重 电子传输材料 空穴传输材料 光致发光光谱 TPD 激发态 组成结构 光谱红移 组成材料 光谱分解 相互作用 复合过程 形成机理 电场作用 电场增强 发射光谱 量子效率 发光颜色 

分 类 号：TN383.1[电子电信—物理电子学] TP314[自动化与计算机技术—计算机软件与理论]