多层氧化物复合阴极透明OLED器件

Transparent Organic Light Emitting Diodes Using a Multilayer Oxide as a Composite Cathode

制备了一种采用多层氧化物复合阴极的透明OLED,器件结构为:ITO/MoO3(10nm)/NPB(60nm)/Alq3(65nm)/Al(1nm)/MoO3(1nm)/Al(Xnm)/MoO3(30nm)。所采用的复合阴极结构为MoO3/Al/MoO3(MAM),同时在复合阴极(MAM)与电子传输层(Alq3)中间插入一层厚度为1nm的Al中间层,该薄Al层一方面提高了电极与有机层间界面的平整度,同时增强了电极的导电性;另一方面,在电子传输层与中间层Al薄膜之间形成了良好的欧姆接触,提高了电子的注入能力。改变MAM结构中Al的厚度,获得该透明OLEDs的最佳性能,在Al的厚度为18nm时器件亮度最高,为2 297cd/cm2。

Transparent organic light emitting diodes are developed by using a multilayer oxide as a composite cathode.The device structure is ITO/ MoO3（10 nm）/NPB（60 nm）/Alq3（65 nm）/Al（1 nm）/MoO3（1 nm）/Al（X nm） /MoO3（30 nm）.The composite cathode is MoO3/Al/MoO3（MAM）.A thin Al layer（1 nm） was introduced as an interlayer between the Alq3 electron transport layer and the MAM electrode.On the one hand,the thin Al layer improves the interface flatness between electrode and organic layers,while improving the conductivity of the electrode.On the other hand,electron injection was greatly improved by forming an Ohmic contact between the electron transport layer and a thin Al layer.Then the OLEDs optimum performance is obtained by changing the thickness of Al in MAM.With the Al thickness of 18 nm,the highest brightness 2 297cd/cm2 is obtained.