39.1: Invited Paper: Efficient Color Tunable Light Sources by The Combination of a Transparent and a Non‐Transparent Organic Light Emitting Diodes

Abstract We have fabricated color tunable light sources by combining a transparent and a non‐transparent organic light emitting diodes (OLEDs). This type of color tunable OLED has efficiency losses due to the absorption of a transparent OLED. To minimize the efficiency losses, we have come up with an innovative transparent OLED, which has high transmittance for the light from a non‐transparent OLED and also high bottom to top emission intensity ratio for the light from a transparent OLED. Therefore, the lights from a non‐transparent and a transparent OLEDs could be maximized simultaneously, which resulted in efficient color tunable light sources.