[[Image:OLED Structure.jpg|thumb|center|450px|[http://electronics.howstuffworks.com/oled1.htm Source: How Stuff Works]]]
===Types of OLED construction===
OLEDs can be constructed in a variety of ways to serve a variety of functions. While each type of construction uses the layers described previously, the manner in which each layer is built alters the way the OLED functions. The five most common types of OLEDs are as follows:
:* '''Passive-Matrix OLEDs (PM OLED)''' – These OLEDs use strips of material for the anode and cathode layers which are laid perpendicular to one another forming pixels at their intersections. Electric current can be selectively applied to each anode and cathode strip allowing pixels to be turned on and off separately. This requires external to control the current and, as such, need more power than other types of OLEDs. Nevertheless, PM OLEDs are easy to make and display text and icons very effectively, particularly in small 2-inch to 3-inch screens that are typically found in cell phones, MP3 players, and other small electronic devices. Compared to LCD panels that currently exist on many such devices, PM OLEDs consume far less battery power.
:* '''Active-Matrix OLEDs (AM OLED)''' – Unlike PM OLEDS, AM OLEDs are constructed with continuous film materials. The anode layer overlays thin film transistor (TFT) circuitry that controls the pixels. AM OLEDs use less energy than PM OLEDs and have faster refresh rates which make them suitable for computer monitors, large-screen televisions, electronic signs, billboards, and other large display screens.
:* '''Transparent OLED''' – Constructed with transparent materials for all five layers, a transparent OLED can be made as either a PM OLED or an AM OLED. When a transparent OLED is turned on, light can pass through both the anode and the cathode layer, making this type of useful for heads-up display applications.
:* '''Top-Emitting OLED''' – These types of OLEDs use an opaque or reflective substrate that is useful for smart card applications. This type of OLED is best suited for an active-matrix design.
:* '''Foldable OLED''' – The substrate of this type of OLED is very flexible, allowing the OLED to be folded or rolled up. These OLEDs are very lightweight and durable and are suitable for applications in cell phones and other electronic equipment where displays can be easily damaged. Because of their flexibility, foldable OLEDs could be attached to fabrics with a variety of applications, such as for survival clothing or even mobile advertisements.
[[Image:* '''White Types of OLED''' – These OLEDs emit white light that is brighter, more uniform, and more energy efficient than that emitted by fluorescent lights. They can be made in large sheets and have the potential to replace incandescent and fluorescent lighting in commercial, industrial, and residential applications.jpg|thumb|center|600px]]
