论文部分内容阅读
(1) We investigated solution-processed films ofN.N-Bis(naphthalene-l-yl)-N,N-bis(phenyl)-benzidine (NPB),4,4-bis(2,2-diphenylvinyl)-l,l-bibenyl (DPVBi) and their blends,which were characterized by atomic force microscopy,optical microscope and spectroscopic ellipsometer.We found that the spin-coated small-molecular films of NPB,and blends of NPB and DPVBi were more uniform,and lower density than their vacuum-deposited counterparts.Using the spin-coated films of the blends of NPB and DPVBi as the mixed host (MH),which was doped with blue dye (4,4-bis[2-(4-(N,N-diphenylamino)phenyl)vinyl]biphenyl) and yellow dye (5,6,11,12-tetraphenylnaphacene),we demonstrated a new white organic light-emitting device (WOLED).With the optimized ratio (3∶2) of NPB∶DPVBi in the MH,the WOLEDs we built achieve a maximum luminance of 35822 cd/m2,a current efficiency of 8.3 cd/A at the luminance of 1000 cd/m2,and a stable CIE coordinates with various applied voltages.Our research shows the solution-processed small-molecular films could be used as a new route to fabrication of small-molecular WOLEDs,reducing the cost of devices and avoiding the complexities of the co-evaporation of multiple dopants and host materials in the vacuum deposition.(2) Thin films of N,N-bis-(3-Naphthyl)-N,N-biphenyl-(1,1-biphenyl)-4,4-diamine (NPB),tris-(8-hydroxyquinoline)-aluminum (Alq3) and their blends prepared by spin-coating process were investigated.Experimental results revealed that the film of NPB could be prepared by spin-coating process with smoother surface than that of Alq3,which was attributed to their different molecular structures.Organic light-emitting devices (OLEDs) with emitting layer prepared by spin-coating the blends of NPB and Alq3 exhibited the maximum luminance and current efficiency to be over 10000 cd/m2 and 3.8 cd/A respectively,and when 10-(2-benzothiazolyl)-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H,11H-[1]benzopyrano[6,7,8-ij]quinolizin-11-one was doped in,the current efficiency of 8 cd/A can be obtained.Comparative device performance to the vapor-deposited OLEDs suggested that solution-process could be an alternative route for the fabrication of OLEDs based on Alq3.