6-2:Invited Paper: Development of a Vertically-stacked Color-tunable Polychromatic Organic-light-emitting-diode Device for Roll-to-roll Manufacturing

Abstract

A flexible vertically‐stacked flexible polychromatic color‐tunable OLED have been developed by means of low resistive intermediate electrode technology. The polychromatic OLED has capability to show 16 million colors with 105% NTSC color reproduction. The device can produce arbitrary shape with arbitrary colors, suitable for artistic expressions, just as many artistic painting are using. Independently controlled, red, green and blue light‐emitting layer are stacked vertically. With conventional ITO technology, due to the temperature restriction, it was quite difficult to achieve low resistance on plastic substrate. The reported numbers were all more than 80Ω/ɑ. According to the surface mobility control using Fick's law analysis, low sheet resistance 7.34Ω/ɑ on plastic film was developed. At first, flexible 7.17 cm2 transparent OLED was fabricated for the performance confirmation of transparent electrode. And then polychromatic colortunable OLED with the same size were successfully fabricated on plastic. With optical length optimization for each color stack of polychromatic OLED, more than 100% color reproduction in National Television Committee Standard was achieved by stack design. The polychromatic device can be used for colored illumination, as well as for organic‐light‐emitting display pixels for three times emission than conventional pixel design. The device is fabricated on plastic substrate so that the polychromatic organic‐light‐emitting‐diode device is manufacturable with roll‐to‐roll production line.