Highly efficient and stable white organic light emitting diode with triply doped structure

A triply doped white organic light emitting diode with red and blue dyes in the light emitting layer and a green dye in another layer is proposed. The device structure was CuPc(12 nm)/NPB(40 nm)/ADN:DCJTB(0.2%):TBPe(1%)(50 nm)/Alq:C545(0.5%)(12 nm)/LiF(4 nm)/Al. Here copper phthalocyanine (CuPc) is a buffer layer, N,N′-di(naphthalene-1-y1)-N,N′-dipheyl-benzidine (NPB) is a hole transporting layer, 9,10-di-(2-naphthyl) anthracene (ADN) is blue emitting layer, tris (8-quinolinolato)aluminium complex (Alq) is an electron transporting layer, 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidy1-9-enyl)-4H- pyran (DCJTB), 2,5,8,11-tetra-butylperylene (TBPe), Coumarin6 and deveriative (C545) are red, blue and green dyes, respectively. This device shows a luminance of 21200 cd/m2 at driving current of 400 mA/cm2 and 1026 cd/m2 at 20 mA/cm2. Its efficiency is 6 cd/A and 3.11 Lm/W. It also shows a higher operating stability: the half lifetime is 22,245 h at an initial luminance of 100 cd/m2, while the driving voltage increased only 0.3 V.