Many displays consist of a matrix of pixels, formed at the intersection of rows and columns deposited on a substrate. Each pixel is a light emitting diode such as a PLED, capable of emitting light by being turned on or off, or any state in between. Coloured displays are formed by positioning matrices of red, green and blue pixels very close together. To control the pixels, and so form the image required, either 'passive' or 'active' matrix driver methods are used.

In passive matrix systems, each row and each column of the display has its own driver, and to create an image, the matrix is rapidly scanned to enable every pixel to be switched on or off as required. As the current required to brighten a pixel increases (for higher brightness displays), and as the display gets larger, this process becomes more difficult since higher currents have to flow down the control lines. Also, the controlling current has to be present whenever the pixel is required to light up. As a result, passive matrix displays tend to be used mainly where cheap, simple displays are required.

Active matrix displays solve the problem of efficiently addressing each pixel by incorporating a transistor (TFT) in series with each pixel which provides control over the current and hence the brightness of individual pixels. Lower currents can now flow down the control wires since these have only to programme the TFT driver, and the wires can be finer as a result. Also, the transistor is able to hold the current setting, keeping the pixel at the required brightness, until it receives another control signal. Future demands on displays will in part require larger area displays so the active matrix market segment will grow faster.

PLED devices are especially suitable for incorporating into active matrix displays, as they are processable in solution and can be manufactured using ink jet printing over larger areas.