Efficient organic light-emitting diodes with zinc acetate as an effective electron injection layer

We report on the fabrication of organic light-emitting diodes (OLEDs) using a zinc acetate ((CH3COO)2Zn) layer as the cathode buffer layer. The results show that the device containing a (CH3COO)2Zn interlayer shows improved luminance and efficiency due to the Zn–N bond formation resulting in the occurrence of Alq3 anion and also due to the band bending at the Alq3/Al interface, which is beneficial to electron injection by lowering electron injection barrier. And the devices with structured cathodes (CH3COO)2Zn/LiF/Al and LiF/(CH3COO)2Zn/Al have a higher luminance and efficiency than the LiF/Al cathode-based device.