Organic Light-emitting Devices with Different Hole-injection Layer

Organic light-emitting device have been realized by using 4,4',4 ''-tris{N,-(3-methylphenyl)-N-phenylamin}triphenylamine (m-MTDATA), N,N'-bis-(1-naphthyl)-N,N'-diphenyl-1,1'-biph-enyl-4,4'-diamine(NPB),4,4(-N,N)-dicarbazole-biphenyl (CBP), and NPB: CBP as holes injection layer, respectively, and [2-methyl-6-[2-(2, 3,6,7-tetrahydro-1H, red fluorescent dye 4-(dicyanomethylene)-2-t-butyle-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)4H-pyran (DCJTB), together with well known green fluorescent dye quinacridone (QAD) as emitting layer, tris-(8-hydroxyquinoline) aluminium (Alq(3)) act as electron transport layer. WOLEDs was obtained with CBP or NPB: CBP as holes injection layer, the Commission Internationale de l'Eclairage (CIE) coordinates of the device C and D change from (0.408,0.4202) at 4 V to (0.4465,0.4646) at 11 V, (0.248,0.2791) at 4 V to (0.4616,0.4366) at 16 V, respectively. Its maximum luminance and maximum current efficiency of the device A was 3126 cd/m(2) at 11 V, and 2.28cd/A at 13V, respectively.