OLED DISPLAY

OLED

OLED panels are made from organic (carbon based) materials that emit light when electricity is applied through them. Since OLED's do not require a backlight and filters (unlike LCD displays), they are more efficient, simpler to make, and much thinner - and in fact can be made flexible and even rollable. OLED's have a great picture quality - brilliant colors, infinite contrast, fast response rate and wide viewing angles. OLED's can also be used to make OLED lighting - thin, efficient and without any bad metals.

How does OLED's work

The main component in an OLED display is the OLED emitter - an organic (carbon-based) material that emits light when electricity is applied. The basic structure of an OLED is an emissive layer sandwiched between a cathode (which injects electrons) and an anode (which removes electrons). Modern OLED devices use many more layers in order to make them more efficient and durable, but the basic functionality remains the same.

How an OLED panel is made

An OLED panel itself is made from a substrate, backplane (electronics - the driver), front plane (the organic materials and electrodes as explained above) and an encapsulation layer. OLED's are very sensitive to oxygen and moisture and so the encapsulation layer is critical.

The substrate and backplane of an OLED display are similar to those of an LCD display, but the front plane deposition is unique to OLED's. There are several ways to deposit and pattern the organic layers. Currently most OLED displays are made using vacuum evaporation, using a Shadow Mask (FMM, Fine Metal Mask) to pattern. This is a relatively simple method but it is inefficient (a lot of material is wasted) and very difficult to scale up to large substrates.

Some OLED materials are soluble, and these can be deposited using printing methods - mostly ink-jet printing. This technology is not commercialized yet, but OLED makers hope that ink-jet printing may be a scalable, efficient and cheap way to deposit OLED's.