When we mention LED lighting, everyone thinks of bright light, the production of which does not require much energy. It should note that LED stands for Light Emitting Diode, representing a semiconductor diode that emits photons, i.e., light. Of course, an electrical circuit requires a certain amount of energy.
In addition to the visible spectrum, LEDs can also emit invisible light. It is in the infrared and ultraviolet spectrum. However, hardly anyone thinks about the brief history of the origin of LED lighting. The process of creating LED bulbs was neither simple nor quick.
How was the LED light bulb created?
The classic incandescent light bulb has been used for lighting throughout the last century. We know its disadvantages - they last a short time and consume much energy (they are not energy efficient). Measurements show that only 5% of energy is transformed into light. In contrast, the remaining amount is used for heating the filament, that is, for thermal energy, which in this case has no positive effect on the primary purpose of the light bulb.
A slight shift for the better occurred during the 30s of the 20th century. The fluorescent lamp was created. Their light consumes less electricity, but this solution is not the most environmentally friendly. Namely, there is a lot of poisonous mercury in fluorescent tubes, and the light is not consistent but flickers.
Light-emitting diodes were created entirely by accident in the early 60s of the last century. Scientists Pitman and Beard were trying to make a laser, and they got an LED!
However, the first LED light emitted an invisible spectrum - infrared - later, it was widely used for applications in some devices such as remote control.
What happened after that?
After realizing the importance and usability of LED bulbs, they worked on further development decades after their discovery. The main problem was the impossibility of obtaining blue light, which was a step towards the sought-after white light.
The world's largest and most influential companies joined the race to find a good LED light bulb. A brief history of the origin of LED lighting says that gallium nitride is the most crucial element for achieving the set goals. However, it is challenging to manufacture. It took three decades to realize that the solution lay on the other side. These are semiconductor materials.
Japanese physicist Shuji Nakamura was employed by a small company called NICHIA. He thought he had a solution to getting blue light. The small amount of money he had at his disposal forced him to take a detour and make red and infrared diodes. He used waste materials as raw materials, which he later processed by hand.
Source: The Japan Times
What did Nakamura achieve?
It was a difficult and long-term job, which despite all efforts and knowledge, did not give the desired result. Nevertheless, he gained specific expertise and experience, so Nakamura came up with a "crazy" idea that almost no one supported. He set out to develop a blue LED using a gallium nitride compound.
Why was the Japanese scientist so determined to make a blue LED? The answer is simple - it was his doctoral dissertation.
The doctorate ruled
Nakamura had to get a doctorate to continue his scientific work and stay as the university chair. But why precisely on an LED bulb? And here, the answer is highly pragmatic - there were not many works on that topic, so he had a massive room for maneuver and a chance to go down in history.
Unlike Nakamura, most of the world's companies did not want to spend too much time, so they used costly technology to produce LED bulbs. But it did not give adequate results either - it was ineffective in producing blue light, and unwanted events often occurred in laboratories. To be precise, to explosions!
In a way known only to him, the Japanese managed to convince the management of the company where he worked to acquire the necessary equipment for producing compounds that Nakamura considered required for the production of the blue LED. With his knowledge so far, he did not have to start from a blank sheet of paper but immediately adapted the equipment to new needs.
Hard work results in rewards
And it didn't take long for him to reach his goals. In just 12 months, he synthesized gallium nitride in the laboratory. The production costs of LED chips were thus significantly reduced, and the blue LED became a reality. It was the basis for the emergence of white light. Namely, white light is obtained when the LED chip for blue light is coated with such a layer of phosphor.
It was a real revolution. Small in size, extremely powerful in the amount of emitted light, but incredibly economical, LED bulbs have started a process in the lighting industry. Today, LED bulbs are used in a considerable number of devices, but also the auto industry. LED bulbs have contributed significantly to traffic safety because the light they emit exceeds all others - in terms of quality and intensity.
Nakamura received the Nobel Prize in Physics for this invention, and the award was presented to him in 2014.
Due to the dedicated work of the Japanese scientist, we are now able to enjoy all the benefits of LED lighting, to combine it according to our own taste, wishes and needs with minimal energy consumption! LED bulbs also contribute to the environment.