【摘要】 以铱配合物红色磷光体为掺杂剂,制备了基于TPBi材料的红色电致磷光器件,其结构为ITO/CuPc/NPB/TPBi:Btp2Ir(acac)/TPBi/Alq/LiF/Al.取得了在x=0·62,y=0·35的色度下,效率最高达2·43cd/A;电流密度为20mA/cm2时,亮度431cd/m2;电流密度为400mA/cm2时,亮度4798cd/m2的结果.讨论了不同的发光层厚度影响器件色度和效率的主要因素:当发光层厚度小于15nm时,发光层中掺杂剂分子不能充分俘获从NPBHOMO能级上隧穿的空穴以及三线态激子之间相互作用导致的发光自猝灭是影响器件性能的主要原因;但当发光层厚度大于20nm时,无效的发光层以及发光层中的猝灭中心可能是造成器件效率下降的重要因素.更多还原

【Abstract】 Devices using red phosphorescent dye as dopant with exciton blocking layer were constructed. The device structure is ITO/CuPc/NPB/TPBi:Btp-2Ir(acac)/TPBi/Alq/LiF/Al. The EL spectra, luminance-current, efficiency-current characteristics of the device have been investigated. At the CIE coordinates x=0.62,y=0.35,efficiency 2.43cd /A has been achieved. At 20mA/cm~2 and 400mA/cm~2, luminance is 431cd/m~2 and 4798 cd/m~2, respectively. The effects of the emitting layer thickness on efficiency and EL spectra of the device have been studied also. With the decrease of the emitting layer thickness, efficiency decreases and the blue band of the El spectra increases. For the thickness d<15nm, the efficiency significantly decreases. This is mainly because of pronounced triplet-Triplet (T-T) annihilation. Another factor which reduces the efficiency and impairs the color is incomplete capture of holes channeling from Btp-2Ir(acac) HOMO energy level. For the thickness d>20nm, the decrease of the efficiency is attributed to the added invalid emitting-layer and more annihilation centers.更多还原