OLED Display

Display is one of the important application fields for OLEDs because OLEDs have several excellent features as displays. Before describing OLED display technologies, this chapter first describes the unique features of OLED displays in comparison to liquid crystal displays (LCDs), which are used for the majority of current displays. OLED displays are divided to static drive, passive-matrix drive and active-matrix drive by the driving methods. Static drive can allow only very low information contents. Passive-matrix OLEDs (PM-OLED) can allow medium information contents, having been applied, for example, to car audio, sub-display of mobile phone, small size main display of mobile phone. On the other hand, active-matrix OLEDs (AM-OLED), which are usually driven by thin film transistors (TFTs), can allow large information contents. Therefore, AM-OLEDs can be applied to wide ranges of applications such as mobile phone, smart phone, tablet display, and TV. In AM-OLEDs, the TFT technologies are different from those for AM-LCDs. This chapter describes the TFT materials and TFT circuit technologies for AM-OLED displays.