A more energy efficient light bulb has been discussed, tested, and used by scientists for decades. This bulb is known as the LED (Light Emitting Diode) light bulb. LED lights are versatile bulbs, found in many everyday devices from cell phones to traffic lights. The key advantage of LED light bulbs is their energy saving capabilities; they are longer-lasting and convert most of their energy into light as opposed to heat. With more and more people switching from traditional incandescent light bulbs to LED light bulbs, one may wonder what lies behind this more efficient technology. How do these LED bulbs actually light up?
The first concept that is crucial to understanding how LED lights work is the diode. A diode is a basic form of a semiconductor, which allows for the flow of electricity to occur. A semiconductor diode is comprised of two terminals, sometimes described as a pn. One side of the semiconductor is attached to the n (negative) side, known as the cathode. The other side of the semiconductor is attached to the p (positive) side, known as the anode. A diode is known as a unidirectional conductor because the electrical current can only flow in one direction, from the p side to the n side.
The activity that occurs in the diode generates light energy. The positive layer has “holes” or openings for electrons while the negative layer has free electrons floating in it. An electric charge causes the electrons to become excited and move from the negative to the positive side. As the electrons flow through the positively-charged holes, the diode gives off light.
In addition to the diode, there are several other components that make up the LED light bulb and allow it to emit light. The anvil is connected to the cathode, a whisker is connected to the anode, and a lens illuminates the light created for distances. A solid, plastic casting protects the LED bulb. It is this plastic casting that marks LED light bulbs as solid-state devices. Solid-state refers to products that have no moving parts. With no moving parts, LED bulbs are more durable and reliable due to decreased friction and fewer breakdowns.
LED light bulbs are poised to take over the lighting market. Investing in these light bulbs is a cost-effective way to increase your energy efficiency. In addition, LED lights are also environmentally friendly. Light emitting diode technology is on track for use in many more commercial and household applications in the near future.