Real-Time Color-Tunable Electroluminescence From Stacked Organic LEDs Using Independently Addressable Middle Electrode

Independently controllable stacked organic light emitting devices (OLEDs) are fabricated by using interconnecting electrode of Al (2 nm)/WO₃ (3 nm)/Au (16 nm) for connecting two primary color OLED units of blue and red. The middle electrode simultaneously functions as the cathode and anode for the bottom and top units respectively with a feature of over 60% optical transmission in a wide wavelength range from 500 to 700 nm such that the color can be tuned in real time from red to blue by changing the bias voltage to the two units. The undistorted primary colors and high efficiency have been obtained through optimizing structure and properly arranging the ordering of the blue and red subpixels.