Solid-state lighting refers to a lighting application that uses light-emitting diodes (LEDs), organic light-emitting diodes (OLED) or polymer light-emitting diodes. While incandescent or fluorescent lamps make use of filaments, plasma and/or gases to create light, solid-state lighting contain semiconductors, which converts electricity into light.

 

It produces visible light through a phenomenon called electroluminescence, which involves passing an electric current through a semiconductor diode, resulting in the glowing of the semiconductor material. Although LEDs have existed for nearly five decades, they did not see much development earlier and were mainly used as indicator lamps in electronic devices including home appliances (TV sets, clock radios) and radio transmitters. However, in the last two decades, LEDs came across technological developments, which facilitated their usage in signal devices such as exit signs and traffic lights, and flashlights. They are also being used in searchlights, indoor and outdoor arrangements, and cameras.

The energy-efficiency factor of SSL lights is what makes them superior over incandescent and fluorescent lamps. A typical incandescent bulb used at home is able to convert around 5% to 10% of the energy they utilize into visible light and the rest is converted into heat (infrared radiation). On the other hand, an SSL device can convert 90% of the energy they use into visible heat, while the remaining 10% is converted into heat.

SSL devices have longer lives than CFLs and incandescent bulbs; they can last for 50,000 hours in comparison to incandescent light bulbs, which last for nearly 1,000 hours. SSL devices would considerably reduce maintenance costs.

Solid-state lighting devices are free of mercury and other hazardous matters. They are highly durable as they do not contain filaments, and can withstand shock and vibrations. They come in a variety of color shades, shapes and sizes, and thus can be used for a variety of purposes.

Although solid-state lamps cost more than CFLs or incandescent lamps, they can ensure a lot of savings, owing to their long lifespan and lower energy consumption.

Thus, all these aspects and benefits indicate that the growth of solid-state lighting systems is certain for general lighting purposes.