History of LEDs



The Evolution of LEDs

Since the beginning of the 21st Century LED usage has exploded, and the technology has grown from minor uses such as radio power indicators into the driving force behind advances in both residential and commercial lighting applications.

If you’ve ever wondered just where these things came from, and whether they’ll still be lighting our homes and workplaces in years to come, you’re not alone. Much has been written about the future of LEDs, but there’s an equal amount to be learned by looking at where this technology has come from in addition to where it’s going.

The Dawn of Time (AKA: about 50 years ago)

LED technology was born in the mid-twentieth century. Semi-conductors were a hot new technology, and there was a wide range of professionals working to develop and exploit advances in the field. By 1962 the light emitting diode as we know it today was in existence.

Like most new technologies, the price for LEDs started out extremely high before plummeting as demand drove innovation. When originally created, a single LED indicator could cost as much as $200. But by the mid-1970s Fairfield technologies had driven that price down to as low as five cents.

But although they were now affordable, LEDs weren’t a plug-and-play technology, and they lived in the realm of technically-savvy makers and tinkerers. The average consumer would have no idea what to do with one of those “odd-looking diode things.”

This was the era when electronics hobbyists could walk into a radio shack and find a drawer full of LEDs for use in their projects. Affordable and robust, many burgeoning engineers and electricians learned to solder on those inexpensive LEDs. So already they were entering the consciousness of the next generation of inventors and technology shapers, but their use was still limited, both in ease and application. Until, that is, the 1990s came along.

White Light, White Heat

The earliest LEDs were only available in red and green– perfect for those On/Off indicators, but far from a universal solution. A wider spectrum of color evaded the grasp of developers until the 1990s, when a trio of inventors in two separate locations produced blue LEDs. For the inventors, this was a discovery that would lead to a Nobel Prize in Physics. For the rest of the world, it was a revolution in waiting.

With the technological hurdle of a blue LED cleared, engineers soon found that a yellow phosphor coating on a blue LED produced a white light. And with that, the next great advance in lighting technology was born.

A New Law and a New Lease on Life

This bring us to the early 2000s, when industry insiders kept predicting an impending boom in LED sales, but the numbers never appeared to support the buzz. Even as solid-state lighting became more useful, more reliable, and more readily available, incandescents were still far and away the most popular lighting technology worldwide. The fact that incandescents were significantly more fragile and far less energy efficient than alternative technology such as LEDs or fluorescents, simply wasn’t enough to shake consumers out of their life-long habits.

With the passage of the Energy Independence and Security Act of 2007, there was suddenly new life in the residential LED lighting markets. The balance of supply and demand suddenly tipped, and manufacturers were able to push production costs of LED lamps to all-time lows, which created a positive spiral of affordability and popularity: the cheaper LEDs got, the more demand rose, and the more demand rose, the more production and affordability improved.

The same was true for compact fluorescent lights (CFLs), but the regulatory burden associated with CFLs (due to mercury levels) and the unique “squigley” look of CFLs drove consumers towards LEDs. This increased demand incented manufacturers to increase operations, which allowed for greater benefits of scale and drove prices down, which in turn boosted demand further. Suddenly LEDs could be found in flashlights, streetlights, headlights, and they began appearing in light fixtures in homes across the country.

Flexibility and Fit

But manufacturers weren’t content to simply produce more LEDs. They also pushed research into new solid-state formats. Organic light emitting diodes (OLEDs) and microLEDs (uLEDs) have begun to step up as the next generation of LED applications. Popular because of their design flexibility, they also have a literal, physical flexibility that allows for a much broader range of applications. If you’ve seen a concept phone or computer screen they can roll up like a newspaper, then you’ve seen OLEDs in action.

By tracking the history of the LED, we can see a consistent principle of innovation driven by consumer demand. As the lighting industry continues to evolve, lighting professionals and customers can anticipate upcoming trends by tracking upticks in demand and any pending governmental incentives. Knowing the past may not let us change the future, but it does position us for success yet to come.


With over a decade of construction experience, Dan Stout writes articles that help demystify the industry for both contractors and customers. Visit him at www.DanStout.com.


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