I was surfing for info on Apple's new tablet and found a reference to OLEDs and ...

>And you didn't have a clue what they were, right?

Uh ... right. But, since curiosity is my forte, I looked about and larned that OLEDs can be used in a neat variety of ways: Generate a display that you can fold up and stick in your pocket. Paste to a wall, like wall paper ... and they can display moving images. Provide bendable and very thin PC monitors. Folding newspapers ... with a PC brain. Make lighting fixtures that ...

Flexible display!

>Wait! What's OLED mean?
I though you'd never ask.
Remember that a Light Emitting Diode (LED) is a material that emits light when a voltage is applied.
Remember, too, that a source of voltage has two polarities: A negative cathode which ejects electrons and a positive anode which sucks up electrons.
Here's what I larned.

There are organic (carbon-based) molecules (like polyaniline), that have the property that You apply a voltage across a layer of molecules. Electrons get dragged out of the atoms. They leave a "hole". If you allow the electrons to plop back into the holes, light is emitted. Various organic molecules provide various frequencies of visible light.

In OLEDs, there are (typically) two layers: Emmisive & Conductive. The Emmisive layer is supplied with electrons by a Cathode. The Anode sucks electrons from the Conductive layer, leaving holes. Electrons in the Emmisive layer are attracted to the Anode and travel across the Emmisive/Conductive boundary. They drop into the holes in the Conductive layer and ...

>And emit light!
You got it.
However, I think the holes in the Conductive layer actually migrate to the Emmisive layer and inkjet technology can be used to deposit OLED material and ...

>So why are you writing about this stuff? Isn't it explained elsewhere? Can't I just google?
Uh ... yes. That's where I get it, but I read stuff like:

"polyaniline (PANI) and Indium/tin oxide (ITO) as the transparent anode of a polymer light emitting diode with poly(2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene), (MEH-PPV), as the active layer" And the diagrams are too complicated for me ... my eyes glaze over, so I'm hoping to understand just enough without overtaxing these grey cells. >That'll be difficult. Thanks.

OLED structure