Active-matrix OLED

Active-matrix OLED (Active-matrix organic light-emitting diode or AMOLED) is a display technology for use in mobile devices and televisions. OLED describes a specific type of thin film display technology in which organic compounds form the electroluminescent material, and active matrix refers to the technology behind the addressing of pixels. AMOLED technology is currently used in mobile phone and media players[1] and continues to make progress towards low power, low cost and large size (for example 40 inch) for applications such as televisions.


Technical
An active matrix OLED display consists of a matrix of OLED pixels that generate light upon electrical activation that have been deposited or integrated onto a thin film transistor (TFT) array, which functions as a series of switches to control the current flowing to each individual pixel.
Typically, this continuous current flow is controlled by at least two TFTs at each pixel, one to start and stop the charging of a storage capacitor and the second to provide a voltage source at the level needed to create a constant current to the pixel and eliminating need for the very high currents required for passive matrix OLED operation.
TFT backplane technology is crucial in the fabrication of AMOLED displays. Two primary TFT backplane technologies, namely polycrystalline silicon (poly-Si) and amorphous silicon (a-Si), are used today in AMOLEDs. These technologies offer the potential for fabricating the active matrix backplanes at low temperatures (below 150°C) directly onto flexible plastic substrates for producing flexible AMOLED displays