They are already illuminating the first smartphone displays and a few small but bespoke TV sets. I’m talking about OLEDs, also known by the brand name AMOLED in the mobile phone sector. This technology is also set to play a role in the automotive sector in the future.
The abbreviation „OLED“ stands for organic light-emitting diode, something which causes much confusion. Organic? One of the most common questions about them is: „Does that mean they are manufactured from sustainable raw materials?“ Some people then think back to dim and distant chemistry lessons and recall that „organic chemistry“ is the branch of the subject that deals with carbon compounds. It has nothing to do with eco-friendliness and the like. The same is true of OLEDs which are, in fact, a new kind light-emitting semiconductor and have very little in common with classical LEDs.
In other words, an OLED is a slim illuminated surface. This is a great advantage in tail lights, for instance. The light emitted by current light sources such as incandescent lamps, but also ordinary LEDs, is more or less punctiform. However, tail lights and brake lights are supposed to light up over an area and all manner of optical tricks are required to make these punctiform light sources illuminate a surface. OLEDs, on the other hand, generate a luminous surface right from the word go. That is a clear technical advantage. And the new light source opens up a whole range of new design possibilities, too. Tail lights and brake lights can be positioned directly on body parts. The range of possible shapes and forms is endless – limited only by the regulations that apply to all automotive lights. An OLED need not necessarily be rectangular, square or round. Designers can quite literally look forward to a bright future developing illuminated emblems or characteristic body components. They’re already dreaming of illuminated radiator grilles – the elements that give cars their „face“. Or of brake lights positioned high up on the rear window that are almost transparent when unlit. OLEDs are also likely to prove very advantageous in interior lighting and, of course, instrument panels, too.
Until recently, such ideas belonged to the realm of science fiction. A number of crucial aspects still made OLEDs unsuitable for use in cars. Temperature stability for one. The automotive industry is very stringent in this context. Components must be able to withstand temperatures of at least 85°C for a specific period, which makes sense when you consider that even the interior can soon heat up to a temperature of 70°C on a hot summer’s day. Indeed, in some areas of the car, it is mandatory that the components can withstand as much as 105°C. About three years ago, OLEDs which could withstand the magic temperature of 85°C for two to three hours were first launched on the market. But for many carmakers, this still didn’t go far enough.
Osram has now made a great leap forward in its research. The company has developed the first OLEDs which can withstand 85°C for several hundred hours. This does not mark the end of the development process, but it does mark the first realistic chance for the new lighting technology to be used in automotive applications. Specialists expect OLEDs to make their automotive debut in the next or next-but-one generation of vehicles. But designers are already toying with the new technology. They’d rather use it today than tomorrow.
So, are we all clear about what the term „OLED“ means now? Or is anyone out there still convinced they once read something about some kind of purely biological light? If so, you may actually be right. But you’re no doubt thinking of bioluminescence. Glow worms can produce it – maybe cars will too, one fine day. I’m sure the researchers are working on it.