Magnified image of the AMOLED screen on the Nexus One smartphone using the RGBG system of the PenTile Matrix Family (Photo taken with a 200x digital microscope by Matthew Rollings. It shows the RGB arrangement of the pixels on Google's Nexus One AMOLED screen with PenTile matrix pixel arrangement.)
An AMOLED, which refers to Active Matrix Organic Light Emitting Diode, is basicly a stack of cathode, organic, and anode layers respectively placed on top of a substrate that contains the circuitry. As seen in the image above each pixel contains red, green and blue parts and the pixels are defined by the deposition of the organic material in a continuous, discrete “dot” pattern. Each pixel is activated by a voltage applied to the cathode and anode materials from the circuitry on the substrate, activating the organic layer. The main advantages of an AMOLED screen over a conventional TFT lies on the brightness, true color and depth of field. As there is no backlighting in AMOLED screens, black regions have a deeper feeling. Another advantage is there is nearly no loss of visual quality at different angles and the visibility is far more better than the TFT at outdoors.
Sources:
1) http://www.densitron.com/uploadedFiles/ProtectedDocuments/AMOLEDPresentation.pdf
2) http://en.wikipedia.org/wiki/AMOLED
3) http://www.oled-display.net
