The amazing magical LED: Has it really been fifty years already?
Simply a better way than making wires white-hot
And that's pretty much where LEDs stayed for about a decade: the preserve of very specific applications and used in electronics kits, but not really entering mainstream or widespread use as we see today.
Arguably the next big inflection point came courtesy of the Nichia Corporation in September 1991, when Naruhito Iwasa identified a production-friendly way of creating bright white LEDs through more advanced semiconductor doping techniques.
By revising his methods Iwasa redefined a 100x brighter blue LED in 1993, followed by a pure green version in 1995. Nichia continued to blaze the LED trail, forging the way for all the super-bright white and colour spectrum LEDs we see around us today.
Following the race to produce LEDs in multiple colours, the key focus of research quickly turned to brightness. The modern success of the LED in consumer and industrial applications can be attributed to the continuing evolution of super-bright LEDs, which some experts have noted appear to follow a kind of Moore's Law - becoming twice as bright every 18 months. Today LEDs are being developed that can produce 250 lumens per watt, and progress is extremely rapid.
As a result, our homes and workplaces can now be lit very effectively with LED bulbs. Every traffic signal in the US is now lit by LEDs. Every light in every new production vehicle is soon expected to be an LED rather than an incandescent bulb. New offices and retail buildings are being designed to be 100 per cent LED lit. And the extreme efficiency of LED lighting is allowing solar charged units to illuminate the developing world without the need for mains electricity.
Other than lighting, the most notable use of LEDs in our lives today is undoubtedly the introduction of brighter, more energy efficient screens. Multiple innovations in organic LEDs (OLEDs), which integrate a film of organic compound as the emissive electroluminescent layer, have helped transformed screen technology.
OLEDs do not require a backlight, so manufacturers have been able to produce screens that are thinner, lighter and of far higher contrast to earlier Liquid Crystal Display (LCD) or plasma designs. Our monitors, televisions, laptops, smartphones and tablets are now capable of delivering a picture quality that makes us grin without forcing us to recharge often enough to make us groan.
Fifty years on, lighting purists criticise LED light for not being "warm" enough, especially white light in a domestic setting, but the truth is that the relentless and rapid evolution of the LED makes it too efficient to ignore.
It's likely that the end price of an LED bulb will go down by half between now and 2020, which along with its impressive energy efficiency gains, boosts the LED's economic and green credentials so much higher than incandescent light that for most markets the LED is now a no-brainer. On average an LED bulb uses upwards of 80 per cent less energy than a traditional 60W incandescent bulb*, costs a tenth of the price to run each year, and lasts 50 times as long.
And, in the world of technology, the applications are seemingly endless. Traditional LEDs are used in pretty much every device indicator panel and remote control we use daily, as well as the disc drives of our computers, media players and games consoles.
What's next? With innovation as rapid as that experienced over the last 50 years, you should keep a (shaded) eye out for: huge billboards, multi-screen video walls, medical implants, cryptic watches, modern art, interactive medical centres, tattoos, the open source satellite initiative, and gestural music ware. Also, keep an eye on groups such as the Li-Fi Consortium, who are working on next-generation optical wireless communications. ®
*Although it may be worth noting that in the winter, when buildings are warmed by thermostat-controlled central heating, the energy which the old incandescent bulbs used to "waste" in the form of heat will now be automatically replaced by the heating running a little harder and more often. However gas for the boiler is cheaper than electricity for the lights, and when the heating is off this won't happen (and the air-conditioning, if present, won't have to fight the lights so hard in summertime). - Ed