Full-color OLED Displays

An individually addressable double-sided 1.5 inch AM-OLED display was recently presented by AU Optronics these are the thinnest OLED devices for mobile applications [60]. Samsung SDI has demonstrated a 17 inch UXGA-AMOLED display suitable for HDTV application in home entertainment [61]. 

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Shibusawa, M. Kobayashi, M. Hanari, J. Sunohara, K. Ibaraki, N. 2003. A 17-inch WXGA full-color OLED display using the polymer ink jet technology. IEICE Trans. Electron., E86-C(ll) 2269-2274. 

Each of the techniques described above has unique strengths and weaknesses, and the optimum device structure for commercial full-color displays will also be heavily influenced by the ease with which it can be mass-produced. Currently full-color OLED displays have been manufactured commercially by using two of the above described techniques only, i.e., (a) side-by-side pixels deposited by high-precision shadow masking and (b) using white OLEDs and color absorption filters. 

A Yoshida, S Fujimura, T Miyake, T Yoshizawa, H Ochi, A Sugimoto, H Kubota, T Miyadera, S Ishizuka, M Tsuchida, and H Nakada, 3-Inch Full-Color OLED Display Using a Plastic Substrate, Proceedings of the 2003 Society for Information Displays International Symposium Digest of Technical Papers, Vol. 34(Book 2), Baltimore, 2003, pp. 856— 859. 

FIGURE 10.7 Power consumption simulation for a 2.2-in. full-color OLED display using Universal Display s phosphorescent OLEDs, small-molecule fluorescent devices, and polymer OLEDs along with a comparison of the power consumed by an active-matrix liquid crystal display backlight. R G B= 3 6 1, 50% polarizer efficiency, and 30% of pixels lit. (From Mahon, J.K., Adv. Imaging, June, 28, 2003. With permission.)... 

Sugimoto, H. Kubota, T. Miyadera, S. Ishizuka, M. Tsuchida, H. Nakada, 211 Invited Paper 3-inch Full-color OLED Display using a Plastic Substrate, SID Symposium Digest of Technical Papers 2003, 34, 856-859. 

Figure 13-19. Schemes to achieve red, green, and blue pixelation for full color OLED display panels.

Helber, M., Alessi, R, Burburry M. et al. 2007. Color filter formulations for full color OLED displays High color gamut plus improved efficiency and lifetime. SID Inti. Symp. Dig. Tech. Papers 38 1022. 

Mameno, K., Suzuki, K., Ichikawa, S. et al. 2002. Active matrix full color OLED displays with high efficiency white OLEDS and ON-chip color filters. Abstracts of the 8th lUMRS International Conference on Electronic Materials G-06, June 10-14, 2002, Xian, China. 

SA VanSlyke, A Pignato, D Freeman, N Redden, D Waters, H Kikuchi, T Negishi, H Kanno, Y Nishio, and M Nakai, Linear Source Deposition of Organic Layers for Full-Color OLED, Proceedings of the Society for Information Display, Digest of Technical Papers, Vol. 33(Suppl. 

OLEDs are obviously able to produce light with virtually every color in the CIE chromaticity diagram but the optimum inexpensive method to manufacture a pixeiatcd full color display is not yet established. The difficulty lies in patterning OLED materials with standard photolithographic methods. Five schemes to achieve color have been suggested, as illustrated schematically in Figure 13-19. 

The simulation discussed above was based on full color produced by individual red, green, and blue emitters. Other full-color reproduction approaches have been proposed for OLED displays including color from blue emitter by means of energy down conversion fluorescent filter [177], and color from white emitters by means of transmission color filter sets similar to that used in LCD industry [178,179]. Table 1.5 compares the EL efficiency of equivalent white... 

Early displays [8] based on vapor-deposited OLEDs were simple alphanumeric devices. More recently, there have been rapid increases in the complexity of these devices. In 1996, Pioneer Corporation demonstrated a monochrome 64 x 256 pixel OLED display [9] that was subsequently developed into a product and was incorporated into automobile stereos (see Figure 7.2). Today full-color, high-resolution vapor-deposited OLED displays as large as 24" have been developed [10]. 

One of the most obvious markets for thin-film vapor-deposited organic materials is in flat panel displays [123], a market currently dominated by LCDs. Over the last two decades, a great improvement in the lifetime and efficiency of OLEDs have been achieved. OLED displays can already be found in simple applications such as automobile stereos, mobile phones, and digital cameras. However, to exploit the advantages of the technology fully, it is necessary to pattern the OLEDs to form monochrome, or more preferentially, full-color displays. This section will consider the difficulties involved in addressing such displays (either passively or actively) and the variety of patterning methods that can be used to produce full-color displays. 

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