利用溶液旋涂的方法,通过改变复合功能层中poly(N-vinylcarbazole)(PVK)和N,N'-bis-(1-naphthyl)-N,N'-diphenyl-(1,1’-biphenyl)-4,4'-diamine(NPB)的质量比,制备结构为indium-tin—oxide(ITO)/PVK:NPB/2,9-dimenthyl-4,7-diphenyl-1,10-phenanthroline(BCP)/Mg:Ag的有机电致发光器件,并对器件的电致发光特性进行了表征。研究结果表明,当复合功能层中PVK和NPB的质量比为1:1时器件性能最好,在该器件的电致光谱中,除了NPB的本征谱峰外,在长波方向还出现了一个位于640nm处的谱峰,这是PVK和NPB产生的电致激基复合物发光,并且随着驱动电压的增加,电致激基复合物的发光强度也相对增强。
Organic light emitting diodes (OLEDs) have been extensively investigated and significantly improved over the past two decades. The mechanism for electroluminescent (EL) phenomenon involves in the injection of holes from anode and electrons from cathode under forward bias voltage, then the hole-electron forming the exciton, and light emission through the radiative recombination of excitons. Due to the superior achieved performance, OLEDs are potential candidate not only for next generation displays, but also for solid state lighting application which requires high efficiency and low operating voltage. Through proper material design/choice and device fabrication, various colors of bright luminance have been developed for use in singleor full-color application. Among various colors, white organic light-emitting diodes (WOLEDs) draw particular attention as their highly potential application in blacking, full color application, as well as in lighting purposes. So far, a variety of methods have been proposed to achieve a WOLED, such as ( Ⅰ ) a muhilayer device with blue, green, and red emissive layers, ( Ⅱ ) a doped device with a host material and blue green, and red fluorescence dyes, ( Ⅲ ) a single-emission-layer device with white emission material, (IV) excimer and exciplex emission, and ( Ⅴ ) stacked structure. About IV, white-light emission can be obtained from a bilayer device using two blue-emitting polymers, in which an exciplex emission at the bilayer interface occurs in addition to an emission from one of the emitter. In addition, finding a simple fabricating way to realize fullcolor OLEDs is also an important and imperative approach to reduce manufacturing cost in industrial produc tion. In this work, OLEDs were fabricated with a simple structure of indium-tin-oxide (ITO)/poly( N-vinylcarbazole) (PVK) : N, N'-bis-( 1-naphthyl)-N, N'-diphenyl-1, 1'-diphenyl-4, 4'-diamine ( NPB)/2, 9- dimenthyl-4,7-diphenyl-1,10-phenanthroline (BCP)/Mg?