High-Resolution, Multicolor Organic LED Displays
The commercial potential of small format, bright, low power consumptialn displays drives Kodak’s investment in thin-film, low-molecular weight organic electroluminescenl devices. The prototypical small-molecule organic light emitting diode (OLED) consists of a transparent hole-injecting electrode, indium tin oxide (ITO), followed in sequence by the hole-transport layer :N,N-bis( 1 -Naphthyl)-N,N’- bis(pheny1)benzidine (abbreviated NPB), the electron tri~nsport layer tris(8- hydroxyquino1ine)aluinum (AlQ3), and a low work function metal electrode, MgAg( 10: 1)’. To achieve greatest market impact, we must develop efficient, high resolution, multicolor displaysbased on this technology. Consider a 5 cm diagonal VGA (640×480 columns by rows) display. Each pixel may contain 3 sub-pixels, one each of red, green, and blue; or each pixel may contain only one subpixel. Given about 10 pm spacing between pixels, sub-pixels ranging fiom 50 pm by 50 pm to 15 pm by 50 pm may be needed.