The latest milestone in WOLED technology for OLED TV and IT displays: Enhancing efficiency, color gamut, and longevity

Abstract This study introduces recent innovative progress in white organic light emitting diode (WOLED) technology for premium OLED TV and IT displays. By fabricating a four‐stack tandem device consisting of red, first blue, green, and second blue devices in sequence from the anode, we could achieve a current efficiency of the WOLED up to 134 cd/A at 10 mA/cm 2 , resulting in enhanced efficiency for red, green, and blue subpixels after transmitting color filters. The new OLED TV implementing the four‐stack WOLED technology reached luminance levels of 2,900, 1,000, and 400 nit at the average picture level (APL) of 3%, 25%, and 100%, respectively, and a flash peak luminance of 4,000 nit. Since the four‐stack device uses red, green, and blue dopants of saturated color, eliminating yellow green (YG) dopant used for our previous WOLEDs, its color gamut in the Broadcasting service Television (BT)‐2020 standard was widen up to 83%. We will explain how to enhance the efficiency and the lifetime in terms of device structure and materials.