Light of the Future

Light of the Future

Organic Light Emitting Diodes, or OLEDs, seem to be the light of tomorrow. OLEDs have been studied since the 1950s, however only with recent technologies has research deepened. As the name suggests, organic molecules that emit light when stimulated with electricity are arranged as normal diodes on an LED screen. Since OLEDs intrinsically emit bright light, no backlight is required, which in an environment where conserving energy is crucial this property may be useful. Sony has already market OLED computer displays in Japan, and Sony is expected to unveil their displays in the US at the end of 2007.

To make an OLED display, an organic film is essentially printed onto a substrate. As this layer (called the emissive layer) becomes negatively charged, its shape reconfigures, letting the electrons fall to a lower energy level. While falling, the electrons emit light. Since the emissive film naturally emits light, it does not require much energy meaning OLED displays can run longer than LED displays on the same battery. And since individual electrons, as opposed to diodes, emit light, the resolution of OLED displays will eventually surpass that of LED displays. SOLED, or stacked OLED, literally stacks the red, green, and blue light emitting molecules ontop of each other instead of next to each other, drastically reducing the space requirements. OLED screens are approximately ten times faster than LED displays as well.

Technology as common as inkjet printers can be used to print the emissive layer onto virtually any surface, offering a promising future for flexible and portable displays. In fact, on May 25, 2007 Sony unveiled a 2.5 inch flexible display only 0.3 millimeters thick. Architects and designers are also currently using OLEDs in upscale housing for lighting sources, replacing incandescent bulbs. OLEDs actually emit so much light that they can be seen in direct sunlight, unlike most cell phone displays.

However, OLEDs still have many drawbacks. For instance blue light emitting molecules have a lifespan of only 5,000 hours, in comparison to 60,000 hours of modern LED displays. Water can destroy an OLED. So to combat summer humidity manufacturers need to build stronger sealants.

While a promising prospect, the practicality of OLEDs needs to be addressed. Few people would pay eighteen thousand dollars for an eleven inch display that only lasts five thousand hours with the other LED models on the market to choose from. In many manufacturers minds, OLEDS will certainly be the light of the future. However, present day technology first needs to be improved.