NPB厚度对异质结OLED载流子复合区域的调控

通过调控p型半导体N,N′-bis(naphthalen-1-y)-N,N′-bis(phenyl)benzidine(NPB)层的厚度,制备了结构为ITO/NPB/aluminum(Ⅲ)bis(2-methyl-8-quinolinato)-4-phenylphenolate(BAlq)/NPB(0~18nm)/tri-(8-hydroxyquinoline)-aluminum(Alq₃)/Mg:Ag的多层有机电致发光器件.分析结果表明,在该类异质结器件中,NPB不仅可以作为空穴传输材料,在适当的厚度范围内,它还可以起到调控载流子复合区域的作用;当NPB厚度在0~18nm之间变化时,随着其厚度增加器件发光颜色可由蓝色变为绿色.通过器件发光光谱的表征可以得知,器件的载流子复合区域相应地由BAlq层转移至Alq₃层.

Modification Effect of NPB Film Thickness on Charge Carrier Recombination Zone of Heterostructure OLEDs

Organic light-emitting devices (OLEDs) have drawn a large amount of attention due to their potential to be the next generation flat-panel displays instead of current widely using liquid crystal displays (LCDs) since Tang and VanSlyke succeeded in fabricating a high efficient green light emissive OLED driven by low direct bias voltage. 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-electrons form excitons, and light emission appears through the radiative recombination of excitons. Multilayer organic light-emitting diode with the structure of indium tin oxide (ITO)/N,N′-bis(naphthalen-1-y)-N,N′-bis(phenyl)benzidine (NPB)/aluminum(Ⅲ)bis(2-methyl-8-quinolinato)-4-phenylphenolate(BAlq)/NPB(0~18nm)/tri-(8-hydroxyquinoline)-aluminum (Alq₃)/Mg:Ag has been fabricated by changing the film thickness of p-type semiconductor NPB material near to Alq₃3 layer.