We are witnessing a new generation of applications of thin film transistors (TFTs) for flat-panel imaging [1, 2, 3] and displays [4, 5, 6]. Unlike the active matrix liquid crystal display (AMLCD) where the TFT acts as a simple switch , new application areas are emerging, placing demands on the TFT to provide analog functions including managing instability arising from material disorder [3, 6].
In the following sections, we briefly describe the application platforms we have considered in this book, namely flat-panel displays and imaging, along with a summary of performance characteristics of the key TFT technologies used, or being considered, by the large-area electronics industry. While the circuit architectures reported here use examples based on amorphous silicon technology, they are easily adaptable to a broad range of materials families and applications with different specifications.
Organic light emitting diode displays
OLEDs have demonstrated promising features to provide high-resolution, potentially low-cost, and wide-viewing angle displays. More importantly, OLEDs require a small current to emit light along with a very low operating voltage (3–10 V), leading to very power efficient light emitting devices [4–6].
OLEDs are fabricated either by organic (small molecule) or polymeric (long molecule) materials. Small molecule OLEDs are produced by an evaporation technique in a high vacuum environment , whereas, polymeric OLEDs are fabricated by spin-coating or inkjet printing . However, the efficiency of small molecule OLEDs is much higher than that of polymeric OLEDs.