Development of a color-tunable polychromatic organic-light-emitting-diode device for roll-to-roll manufacturing

Abstract

A flexible vertically stacked flexible polychromatic color-tunable OLED has been developed by means of low resistive intermediate electrode technology. The polychromatic OLED has a capability to show 16 million colors with 105% National Television Committee Standard (NTSC) color reproduction. The device can produce arbitrary shape with arbitrary colors, suitable for artistic expressions, just as many as those used in information displays. Independently controlled red, green, and blue light-emitting layers are stacked vertically. With conventional indium tin oxide technology, because of the temperature restriction, it was quite difficult to achieve low resistance on plastic substrate. The reported numbers were all more than 80 Ω/□. According to the surface mobility control using Fick's law analysis, low sheet resistance 7.34 Ω/□ 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 color-tunable 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.