新型苯乙烯衍生物掺杂的蓝色及白色有机电致发光器件

Blue and white organic light emitting diodes based on a new stilbene derivative dopant

研究了新型高效蓝色掺杂剂EBDP的电致发光性能.分别以EBDP为掺杂剂制备了结构为氧化铟锡(ITO)/酞菁铜(CuPc)/N,N′-二(1-萘基)-N,N′-二苯基-1,1′-联苯-4-4′-二胺(NPB)/2-叔丁基-9,10-二-(2-萘基)蒽(TBADN):EBDP/8-羟基喹啉铝(Alq3)/LiF/Al与ITO/CuPc/NPB/TBADN:EBDP:4-二氰亚甲基-2-叔丁基-6-(1,1,7,7-四甲基久咯呢定基-9-烯基)-4H-吡喃/Alq3/LiF/Al的蓝色和白色电致发光器件.蓝色器件在400mA/cm2电流密度驱动下的发光亮度达26961cd/m2,最大发光效率为8·29cd/A,在20mA/cm2电流密度驱动下的发光亮度为1597cd/m2;白色器件在400mA/cm2电流密度驱动下的发光亮度达32291cd/m2,最大发光效率为8·31cd/A,在20mA/cm2电流密度驱动下的亮度为1413cd/m2.测量了器件的发光效率与电流密度关系,随电流密度增加发光效率的衰减很缓慢,说明掺杂剂的激子-激子湮没较弱,这是由于掺杂剂的非平面结构增加了空间位阻造成的.

In this paper the electroluminescene of highly efficient blue dopant EBDP was investigated. The blue and white organic light emitting diodes with the structure ： indium-tin oxide （ ITO ） / copper phthalocyanine （ CuPc ） / N, N＇ -bis- （ 1-naphenyl ） - N, N＇ - biphenyl-1, 1＇-biphenyl-4-4＇-diamine （ NPB ）/2-t-butyl-9, 10-di-（ 2-naphthyl ） anthracene （ TBADN ） ： EBDP/tris （ 8- hydroxyquinoline） aluminum （ Alq3 ）/LiF/Al and ITO/CuPc/NPB/TBADN ： EBDP： 4- （dicyanomethylene） -2-t- butyl-6- （ 1,1,7,7- tetramethyljulolidyl-9-enyl）-4H-pyran/Alq3/LiF/Al were studied by using EBDP as blue dopant. For the blue device, the maximum luminance was 26961 cd/m^2, and its maximum efficiency was 8.29 cd/A. The luminance at a current density 20 mA/cm^2 was 1597 cd/m^2. For the white device, the maximum luminance 32291 cd/m^2 and maximum efficiency 8.31 cd/A, the luminance of 1413 ed/m^2 at a current density 20 mA/cm^2 were obtained. The slow decrease of efficiency with the increase of current density indicates weak exciton-exeiton annihilation, which results from the large sterie hindrance due to a non-planar structure of the fluorescence dye EBDP.