The organic light-emitting device (OLED) has been rapidly developed recently. Because it has so many advantages, Such as active emitting, high brightness, full- color, fast response, compact structure, high contrast, wide view angle, low cost, and can be fabricated on flexible substrates. That is called the third generation display technology. So many companies and laboratory have been doing research and development in this area. However, like many new technologies of the future, many technical...