Fabrication and characterization of double-sided organic light-emitting diodes using silver and nickel as the metal linking layer

• This work presented a novel double-sided emitting OLED.
• Electroluminescent characteristics of the DE-OLEDs at bottom and top sides could be modulated independently.
• A series of metal films composed of Ag or Ni were used as linking layers.
• 20-nm Ag based DE-OLEDs showed the optimal current efficiency and luminance.
• The EL spectrum of the TE-OLED was narrower than that of the BE-OLED.

In this work, a novel double-sided emitting organic light-emitting diode (DE-OLED) was developed, and the effect of several metal linking layers on such DE-OLEDs was investigated. To form a DE-OLED, a metal linking layer was thermally deposited between a bottom-emitting organic light-emitting diode (BE-OLED) and a top-emitting organic light-emitting diode (TE-OLED). A series of metal films of 10-nm Ag, 20-nm Ag, 10-nm Ag/10-nm Ni, and 20-nm Ni were used as the linking layers, and 20-nm Ag based DE-OLEDs show the highest current efficiency and luminance. Two types of DE-OLEDs, including monochromatic and dichromatic, have been fabricated successfully. The EL spectrum of the TE-OLED is significantly narrower than that of BE-OLED because of the microcavity effect in both monochromatic and dichromatic DE-OLEDs. The results indicate that the electroluminescent characteristics of the OLED devices at both (bottom and top) sides can be modulated independently by using the metal linking layer without sacrificing the brightness and color stability of the device.