There are two main types of OLEDs. Some are based on polymers while others utilize small molecules. Flexible, they are thinner than LCDs, as OLEDs require no backlight for their operation. For this reason, they can be far more efficient than LCD displays, and can even be manufactured to be transparent.
In terms of application, OLEDs can be utilized in several different ways. They can be fashioned into a highly efficient display with demonstrable advantages over LCDs, or they can be utilized as a solid-state lamp, in a panelized manner.
Some of the most interesting uses of OLEDs pertain to their application in electronic displays. When compared to LCDs, OLEDs offer a better contrast and a fuller viewing angle, while simultaneously requiring lower power consumption. OLEDs are also far more lightweight, and offer better durability.
As they are flexible, organic LEDs make curved displays on mobile devices possible. Their transparency may also allow for OLEDs to be utilized in windows or car windshields, delivering data in a heads-up display where it would have otherwise been impractical to install one.
Organic LEDs are an eco-friendly nanotechnology, with organic, carbon-based materials like polymers used as the semi-conductive substrate. Though they make beautiful and highly efficient displays (RIM used OLEDs in their Blackberry 10 devices), they also have very practical applications as a light source.
An OLED "light bulb" generally comes in the form of a small panel. They provide a radiant, area-lighting glow, as opposed to the directed lighting of LEDs. Organic LEDs provide a good color temperature, and some panels on the market now can actually be color tuned for the desired warmth. Excitingly, these lamps also do not contain any harmful metals, like mercury, which can be found in CFLs.
As with any emergent technology, however, OLEDs are not without their drawbacks. Currently, consumer-grade organic LED lamps and displays are expensive to produce. GE announced a new manufacturing process in 2008 that would allow OLEDs to be printed in a roll, much like newspapers. The development, which is expected to drive down the manufacturing costs of OLEDs, can also be adapted to create organic solar cells and roll-up displays in the future. The printing process has also been cited to advance the idea of OLED wallpaper, which could be manufactured roll-to-roll, and once applied, radiate light from a section of a wall.
One of the major drawbacks of OLED lighting, however, is the life expectancy of the panels. Like any lightbulb or display, OLEDs don't last forever, though they dim over time, as opposed to suffering a catastrophic failure, like incandescent bulbs. The organic materials used in the devices are particularly susceptible to degradation, though different colors break down at independent rates. Blue luminance degrades by 12%, red by 7% and green by 8%, after just 1,000 hours of usage. Due to this fact, OLED displays, particularly when used in televisions, suffer from color balance issues, though manufacturers have developed various techniques to mitigate this problem.
After an average of just 14,000 hours, blue OLEDs will reach half of their original brightness. This is far less than LCD, LED or PDP technology, each of which are rated at about 25,000 – 40,000 hours to half brightness.
The organic components of OLEDs are also very susceptible to water damage, requiring proper sealing practices to be used during manufacturing. This is particularly important when applied to flexible displays, the longevity of which can be threatened by a sealing failure.
When utilized outdoors, recent advances in OLEDs have made them better than LCDs in bright sunlight. Previously, the metallic cathode in an OLED acted as a mirror, with reflectivity impeding their functions as a display.
Multiple manufacturers are now working to bring organic LEDs to market as an efficient, cost-effective option for lighting and digital displays. Over the next several years, we can expect exciting developments that will change the way we shed light on our homes.