Thiruvalluvar,light-emitting diodes

Thiruvalluvar

 Sri Thiruvalluvar is fondly referred to as Valluvar by Tamils.

 Thiruvalluvar is also revered as an ancient sant, poet, and a philosopher.

 His ‘Thirukkural’, a collection of 1,330 couplets (‘kurals’ in Tamil), are 

an essential part of every Tamil household.

 In the early 16th century, a temple dedicated to Thiruvalluvar was built 

within the Ekambareswarar temple complex in Mylapore, Chennai. 

What are light-emitting diodes and why are they prized as light sources?

Diodes:

 A diode is an electronic component with two terminals: anode and cathode.

 Its primary function is to allow current to fl ow in only one direction.

 It achieves this through a p-n junction, where one side is p-type (holes as primary charge-carriers) 

and the other is n-type (electrons as primary charge-carriers).

 Electrons can fl ow easily from the n-type to the p-type but not the other way, creating one-way 

current fl ow.

 When voltage is applied in the correct direction, current fl ows; in the reverse direction, current 

doesn’t fl ow.

LEDs (Light Emitting Diodes):

 LEDs are diodes that emit light when current passes through them.

 Electrons in the p-n junction have more energy than holes, and when they recombine, they release 

energy in the form of visible light (electroluminescence).

 The band gap is the energy gap between levels where electrons can and can’t fl ow; it determines 

the energy of the emitted light.

 By engineering the band gap, researchers can make LEDs emit specifi c colors of light.

 LEDs can produce all three primary colors (red, green, and blue), allowing for a wide range 

of colors.

 Advances in LED technology have made them more effi cient, durable, and cost-eff ective.

 LEDs have various applications in electronics, displays, lighting, and more.