Composite silver electrode for double-sided-emitting stacked organic light-emitting diode

A reflective composite silver electrode is proposed and characterized as the middle electrode of a stacked organic light-emitting diode (OLED) with double-sided light emission. The proposed electrode is composed of a thermally evaporated stack of LiF (1 nm)/Al (3 nm)/Ag (70 nm) layers. The LiF/Al and the plasma-treated Ag of the electrode function well as the respective cathode and anode of the bottom- and top-emitting stacked OLEDs, with both being of the non-inverted type. Power efficiencies of 10.3 and 12.1 lm/W at 100 cd/m(2) have been measured for bottom- and top-emitting OLEDs, respectively, using dye doping. The stacked OLED having this bipolar middle electrode can be constructed as a two-terminal-only device, allowing for simpler driving schemes in double-side-emitting passive-/active-matrix OLED displays.