We have fabricated a 13.5‐inch top‐emission OLED display including an oxide semiconductor FET element. This display has a high pixel density exceeding 300 dpi and is applicable to a Quad‐HDTV (number of pixels: 3840 × RGB × 2160). There have been few reports on fabrication of OLED displays with such a high pixel density so far. Color display is achieved by combining an EL element having a tandem structure and emitting white light with a microcavity structure and a color filter.

In this study, the device structure of a white tandem OLED is changed to control the emission area to achieve less luminance decay. A long‐life 13.5‐inch 4K flexible CAAC‐OS AMOLED with less color shift and high resolution is fabricated using this long‐life white OLED, transfer technology, and a CAAC‐OS FET.

We have developed a long lifetime OLED display by optimizing each organic layer materials. The lifetime of the new developed blue OLED under 50 mA/cm 2 driving at 85 °C was improved more than four times compared with the previously developed OLED, and achieved longer than 1,500 hours in a real use. The developed OLED display would be useful for automotive application.

Low-power-consumption 6.18" WQHD+ flexible AMOLED displays with highly efficient top-emission type blue OLEDs have been developed. Using a blue emitter with narrow spectrum and short peak wavelength, which indicates deep blue chromaticity, the AMOLED displays show 11% lower power consumption at entire white image.

In this study, the device structure of a white tandem OLED is changed to control the emission area to achieve less luminance decay. A long-life 13.5-inch 4K flexible CAAC-OS AMOLED with less color shift and high resolution is fabricated using this long-life white OLED, transfer technology, and a CAAC-OS FET.