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Lighting Innovation

From Bea Wray

LED lights fascinate me. As we sat around our beautiful tree, we noticed that it was only the blue lights that often burned out. Why is that I wondered? How do these things work anyway?

Of course I had read that the LED (light emitting diode) lights use less wattage and even have a longer lifespan than incandescent lights so they have been my Christmas lights of choice for sometime. However, I haven’t personally tossed the old incandescent light strings. It wasn’t until recently that I realized “less wattage” was 80-90% less! I also hadn’t really explored what was going on inside those little bulbs.

As an innovator and entrepreneur, I am always interested in how things work. With incandescent lights, the color is all about the casing, not the actual light. However, with LED lights, the color is about the current and the microcontroller. The specific color depends on the amount of energy involved and that amount of energy depends on the semiconductor material used. It is fascinating that the same string of lights can change colors with only a press of a single button. The way this works is that each little casing actually has several lights inside and the microcontroller controls which combination is on at anytime. For example, one bulb could be red or blue or both making magenta.

Also, as an innovator and entrepreneur, I am interested in how things were invented. Often the answer is by accident and over time. Sometimes entrepreneurs do identify a problem and then seek a solution. However many times there exists a solution which is seeking the best problem. The process for figuring out applicability for technology often takes a refining of the technology. LED lights are no different. Initially, light emitting diodes were very expensive and thus cost prohibitive for wide distribution. Nick Holonyak Jr., while employed at General Electric was the first to develop light emitting diode in 1962 which was visible as red LED. Later, in 1972, M. George Craford invented a brighter red LED as well as a yellow LED while he was a graduate student at Syracuse University researching with Nick Holonyak. However, in England as early as 1907, Henry Joseph Round noticed that carborundum (silicon carbide) crystal emitted yellowish light when 10 volts was applied. Various observations and evolutions continued until Holonyak’s discoveries. However, LED’s were still so expensive in the 1970’s that they were only used with fiber optics in telecommunications. Eventually Fairchild Semiconductors innovated the production and packaging of LED’s to continually bring down the cost and expand the applicability such that now the technology is widely commercially available.

I still don’t fully understand why it is that on our tree it was mostly the blue lights that struggled. It must have something to do with the semiconductor specifically used for that light. What I did learn in my digging is that the inventors of blue LED’s Isamu Akasaki, Hiroshi Amano, and Shuji Nakamura won the Nobel Prize in 2014. Apparently up until this time the only colors available in LED lighting were not ones that would be used to light a room. However, this high brightness blue LED was more practical for everyday home and business lighting. Thus, the 1.5 million people who lack access to electricity grids can light rooms powered by affordable rooftop or nearby, off-grid solar power. Now that is something worth celebrating!

When the holiday celebrations come to a close, and I take down my tree, I will ponder how many more innovation iterations are still to come with LED lighting, and I will question how I might motivate my own children to explore the possibilities. One thing I won’t question is the decision to say goodbye to any remaining incandescent strings.