LED lights are small, but integral components in our technology. From tiny blips of light that serve as electronics indicators, to large-scale LED clusters that form business signs, these diodes have played an impactful role in the history of electronics and computing. LEDs were a brainchild of the 1960s, an era marked by innovation and competition in the semiconductor field, as researchers strived to propel their companies to the forefront of technology.
As several big players, including Texas Instruments, Bell Laboratories, RCA, and GE jumped into the race, LEDs have developed as increasingly powerful light sources that are energy efficient and safer for the environment.
Initial steps and challenges
Illinois-born GE scientist, Nick Holonyk championed the first visible LED lights in 1962. Prior to his development, other semiconductor researchers focused on infrared, which were not visible to the naked human eye. Holonyk’s first LED glowed a deep red. For years, this was the only color available, and its use was limited. Red LEDs do not have enough output to illuminate large areas, and were confined to remotes and electronics as indicators.
Early LEDs were not very widespread. They required more energy than modern day ones, burned out quickly, and they were difficult to maintain by a consumer market. Another challenge was that they only worked with liquid nitrogen temperatures.
LEDs have a fairly simple construction, consisting of very few parts. A semiconductor wafer is the key element, composed of various chemicals to move electrons from a high-density area to a low density one. Just like turning on a faucet, electricity moves in one direction. Chemical impurities are created within semiconductor wafers to excite electronics, causing the glow that is visible to the human eye. The process of creating impurities is known as doping. This allows LEDs to operate on very little energy, making them far more efficient than incandescent bulbs. Electricity makes a jump from a positively charged material to negatively charged material. That jump releases energy that produces visible light. These pieces are surrounded by a clear plastic, protecting the components and containing them.
Two metal shafts called “leads” (known as the cathode and anode) are connected to the wafers, creating a channel for electricity to flow. Anodes are the longer metal leads, and they are connected to the positive charge of a battery. Cathodes are attached to negative voltage, or the ground. Accidentally swapping the positive and negative attachments can burn out an LED, so take care to wire things correctly when experimenting with LEDs.
Development for lighting
Finding a range of colors for LEDs proved to be a historical challenge. Using LEDs as a primary light source seemed to be unreasonable, as early colors were not ideal for long-range illumination. However, researcher Naruhito Iwasa of the Nichia Corporation was able to change the game, propelling LEDs into office use and inside of traffic lights. Iwasa focused on color and brightness, producing white, blue, and green LEDs that were infinitely brighter than their predecessors.
The future of LED construction
Automatic manufacturing has dropped the cost of LEDs dramatically throughout the decades. Depending on the color and brightness, LED lights are extraordinarily affordable and easy to replace. As televisions and computer displays rely increasingly on LED illumination, their construction becomes ever more thinner, robust, and efficient.
With every year, the cost to produce semiconductors drops, allowing LEDs to be more accessible as a cheap light source. A forecast known as Haitz’s Law predicts that LEDs will become increasingly more powerful each decade. As people seek for eco-friendly alternatives, more attention is garnered by LEDs due to their small electrical demands and big punch.