Kyong-Tae Park

9.2: Sequential Lateral Solidification (SLS) Process for Large Area AMOLED

We have demonstrated that the sequential lateral solidification (SLS) technology can be utilized for the large area AMOLED. An optimized SLS process provides us with polycrystalline Si films with well-controlled grain size and location. The thin film transistors (TFTs) with SLS-processed Si films show high performance with desirable uniformity. 14″ WXGA (1280×RGB×768) AMOLEDs were fabricated with SLS-processed TFT backplanes. We utilized RGB evaporation process with fine metal mask. The novel delta pixel arrangement results in increased aperture ratio and wider FMM process window. The advantage of SLS process will be discussed.

L-2: Late-News Paper: The RGBW Advantage for AMOLED

The combination of white OLED and color filter (CF) is the most mature solution for making large-area AMOLEDs. The system can benefit from introducing a white subpixel. We compared the power efficiencies of RGB and RGBW system. As a basis for the comparison, we also propose a reference video called FC in which every color point in the cubic RGB space has the equal probability of appearance. We found that the RGBW system has 16.7% lower power consumption and 23% lower current stress (thus longer lifetime) for the reference video. We also analyzed various kinds of videos from DVD movies, HDTVs and IT graphics to find that in these actual video materials, there is much more utilization of white so that the power consumption is roughly a half of that for the FC video. The reduction is so significant that the W OLED + RGBW CF system has 60% lower power consumption than the RGB CF system and only 50% higher power consumption than the RGB OLED (no CF).

Reliable Characterization of Microcrystalline Silicon Films for Thin Film Transistor Applications

Despite many years of research on microcrystalline silicon films, these materials have not yet found industrial application as thin film transistors. We discuss difficulties in their accurate characterization and compare the advantages and disadvantages of commonly used characterization techniques. Our results show that no single technique provides a complete characterization of these films, and that a combination of techniques is required for a detailed and reliable picture of the film microstructure. Nevertheless, in the case of optimized films, most of the information on the film microstructure can be derived from spectroscopic ellipsometry alone.

62.2: Adaptive White Extension for Peak Luminance Increase in RGBWAMOLED

RGBW AMOLED panel, compare to the RGB panel, has lower power consumption and current stress and as result — bigger life time. Using special algorithms and RGB subpixels (as additional white) permits to increase brightness of this panel up to 2 times. At the same time its very important to keep panel current at permissible range. We propose an algorithm, what permits to increase brightness of the RGBW AMOLED panel and limit its summary current at the same time.