To Quote " OLEDs have held out the promise of better screens for decades even as LCDs ruled. OLED displays can be thinner, more energy efficient and produce deeper black colors because organic pixels can glow on their own, while LCDs require a backlit panel. They can also be made on flexible plastic for a wider variety of shapes and applications. The challenge has been in creating long-lasting, bright screens at low enough prices."
Well they are here now and you can read about it on this page