LED is an acronym for Light Emitting Diode. LEDs are solid state light sources that in a very fundamental manner convert electricity into light.

 

Yes. LEDs are referred to solid state devices because, unlike other lamp technologies, LEDs emit light from a semiconductor which is a solid object.

 

LED light sources offers 3 key benefits:

Reduction in energy consumption.

Reduction in total cost of ownership.

Reduction in carbon footprint.

 

Luminous flux defines the total lumen output from an LED. It is measured in lumens (lm). Luminous flux is directly proportional to the amount of electricity an LED package can handle.

 

Efficacy is a measure of efficiency. It measures the amount of light/lumen an LED produces per watt of electricity passed through it. It is measured in Lumens per watt (lm/w). Efficacy is an important measure when deciding on choosing LEDs for designing light fixtures as it impacts costs and luminous flux

Chromaticity : The color of an LED is decided by the semiconductor material used. LEDs are now available in a wide variety of colors such as red, green , yellow, orange and blue. However white light, which is the desired light for general illumination applications does not occur naturally and therefore has to be created. As discussed above, there are multiple methods of generating white light from LEDs.  Color quality is measured by Color rendering index (CRI) and  Correlated Color Temperatures (CCT) which are 2 measures of chromaticity. The CRI defines the color while CCT brightness.

Correlated Color Temperature (CCT): This unit is used to describe the how white light appears. It is measured in Kelvin (K). Higher values of Kelvin indicate closeness to natural light and lower values represent warmer colors.

Color Rendering Index (CRI): CRI is a measure of color quality that as the name suggests indicates how well a light source renders colors. In other words, how naturally do colors appear under different LED lights. The higher the CRI (based upon a 0-100 scale), the more natural the colors appear.

 

Inorganic LEDs are the first kind of LEDs invented and therefore are synonymous with LEDs. These LEDs are made of inorganic semiconducting materials such as gallium nitride (GaN). Inorganic LEDs are the LEDs of choice due to their many advantages.

 

Organic LEDs: Organic LEDs also known as OLEDs and as the name indicates, are made from organic semiconductor material. There are two basic types of OLEDs, those that are made of polymers and those that employ small molecules

 

Stands for red, green, and blue, the three primary colors of light. When the primaries are mixed, the resulting light appears white to the human eye. Mixing the light from red, green, and blue LEDs is one way to produce white light (source, DOE)