Study On Illumination Mechanism Of Phosphorescent Organic Electro Luminescent Devices Based On CBP

White organic light-emitting device (WOLED) not only can be used in the field of flat panel displays, carried out low power consumption and full-color display, but also can be applied to other solid-state lighting, extensive application prospect has aroused great interest. This paper reviews the developmental history of OLED devices, the relevant oretical basis and device physics, followed by major researching the exciton lifetime of light-emitting materials, in order to supply the theoretical basis with optimizing the device structures to get the standard near-white emission. Specific results are as follows:we simulate the time-resolved luminescence decay curves of different thickness of four kinds of organic thin-film, through the model of one-dimensional exciton diffusion, three kinds of organic thin-film structures are: CBP/LiF/Al; CBP:FirPic(5%/8% mass ratio of doping)/LiF/Al; CBP:Ir(piq)2(acac) (5%/8% mass ratio of doping) /LiF/Al; CBP:Ir(ppy)3(5%/8% mass ratio of doping) / LiF/Al .By time-resolved luminescence decay curves, we obtaine the exciton lifetimeτof every structure, then through simulating the MATLAB program ,we get D,x0,LD and the above structure's quenching area width is: 8.3nm,41.6nm,41.9nm,42.4nm. When we prepare the doped CBP device, the thickness of light-emitting layer is about 100nm. D,x0 is same for different doped ratios,τ,LD and quenching area width are different, which the variable of LD is no more than 5nm.Using phosphorescent material Ir(piq)2(acac), Ir(ppy)3, Firpic and small molecu- le host material-CBP as the light-emitting layer, prepared three different structures of the white device: a,ITO/CBP:Firpic:Ir(piq)2(acac) /BCP /Alq3 /LiF / Al; b,ITO/CBP:Ir(piq)2(acac) (8% mass ratio of doping)/BCP(Xnm)/ CBP:Firpic(8% mass ratio of doping)/BCP/ Alq3 /LiF / Al; c,CBP:Ir(ppy)3:Ir(piq)2(acac) /BCP(6埃)/ CBP:Firpic(8% mass ratio of doping)/PBD/LiF/Al。We study the electroluminescence spectra of the device, the color coordinates, the color rendering index, when the doped ratio of CBP: Fir (pic): Ir (piq)2(acac) is 200:200:10 ,the effect of structure-a is best; when the interlayered thickness is 29 angstrom,the effect of structure-b is best; when the doped ratio of CBP: Ir (ppy)3: Ir(piq)2(acac) is 100:8:2, the effect of structure-b is best, also achieved the standard white light-emission ,and structure is relatively simple.