What is LED and How Light Emitting Diodes Works?

  • PDF

Introduction to How Light Emitting Diodes Works

Light emitting diodes, commonly called LEDs, are real unsung heroes in the electronics world. They do dozens of different jobs and are found in all kinds of devices. Among other things, they form the numbers on digital clocks, transmit information from remote controls, light up watches and tell you when your appliances are turned on. Collected together, they can form images on a jumbo television screen or illuminate a traffic light.

Basically, LEDs are just tiny light bulbs that fit easily into an electrical circuit. But unlike ordinary incandescent bulbs, they don't have a filament that will burn out, and they don't get especially hot. They are illuminated solely by the movement of electrons in a semiconductor material, and they last just as long as a standard transistor.

What is a Diode?

diode is the simplest sort of semiconductor device. Broadly speaking, a semiconductor is a material with a varying ability to conduct electrical current. Most semiconductors are made of a poor conductor that has had impurities (atoms of another material) added to it. The process of adding impurities is called doping.

Automotive LED light from sunight are extremely reliable.(CE,ROHS,E-MARK verified)  .Sunight has a strong team to control the quality of LED from all aspects. Such us, the LED chips check( brightness pattern, Lumen, humidity, efficiency.

We use the quality PCB (printing Circuit board) to make our LED light only. PCB board is must be clear, vibrating-shock, Right size for OEM adaptor. Proper design.

Befor sales, Sunight have three times to check the quality of LED products.

Sunight’s LED are standing high market in Euro, like Germany, Italian, Uk, USA, Japan.

The price of Sunight LED are slightly high than others from China.

Sunight has built global sales net already. The Sunight products are very popular globally.

The History of L.E.D

1907: Henry Joseph Round discovers the physical effect of electroluminescence. But as he is working on a new radio direction finding method for marine vessels this discovery is initially forgotten.

1962: The first red luminescence diode, type GaAsP, is launched.

1971: LED in other colors are available: green, orange, yellow. There are continual improvements in the output and effectiveness of all LEDs.

1993: Highly efficient InGaN diodes emitting in the blue and green spectrum are demonstrated. The conditions for creating white light are met.

1995: The first LED with white light created by luminescence conversion is launched.

Solid State Electronics Image Gallery

Light emitting diodes form the numbers on digital clocks, send data from remote controls and light up traffic signals. See more solid state electronics pictures.

In the last few years the efficacy of colored LED increased up to amazing 100 lm/W and more depending on the color and driving conditions. A trend which will proceed in the future.

As today’s white LED reaches efficacies up to 40-100 lm/W (efficiency depends on color temperature and color rendering) - they are more and more used in general lighting. In emergency lighting as well as decorative lighting, they are already established in implementation area. Today, also applications such as illuminated advertising benefit from the advantages of LED, particularly by using colored LED-modules.

LED Definition:

A light-emitting diode (LED) is a semiconductor diode that emits incoherent narrow-spectrum light when electrically biased in the forward direction.

Basic principles of LED (Light Emitting Diodes)


  • An LED consists of several layers of semiconducting material
  • When an LED is operated with DC voltage light is generated in the active layer
  • The generated light is radiated directly or by reflections
  • In contrast to lamps, which emit a continuous spectrum, an LED emits light in a certain color
  • The color of the light depends on the used material
  • Two systems of material (AllnGaP and InGaN) are used in order to produce LED with a high luminance in all colors from blue to red and also in white (luminescence conversion). Therefore different voltages are necessary in order to operate the diode in conducting direction


The white LED

To produce white light, the light of blue LEDs is passed through yellow phosphors. The composition of the phosphor determines the light color.

The Chip Level Coating (CLC) process developed and patented by OSRAM ensures a degree of homogeneity in the light produced that other processes cannot achieve.

By selecting appropriate white LEDs, it is possible to offer LED systems with the same light colors as fluorescent lamps (Warm White, Neutral White and Daylight).

Light Colors

LEDs from Sunight are available in the color temperature from 2700K to 15000K and Blue, Amber, Green, Pink, Purple, Red.

2700K-4500K = Warm White (Same with OEM)

4500K-6500K= Pure White (Neutral white)

6500k-8000K= Bluish White (Daylight)

Advantages of Sunight LEDs The Key element to the quality of LED chips.

Trough the lifetime of LED is long, it depends on various influencing factors.


LEDs are Getting HOT

An LED emits light but it hardly emits any UV or IR radiation; the emitted light is cold - illuminated objects are not exposed to heat. LED lighting is therefore ideal for illuminating sensitive objects - for example in museum or shops.

The LEDs themselves (and therefore the entire module) are heated up however by the process by which light is produced. This heat must be transported away from the LEDs.

The life of an LED module depends on the temperature at which it is operated.

The cooler, the higher the lifetime, the brighter the LEDs.

For More Info Please call Varun 7981230551 or Naresh 8179409843 or This e-mail address is being protected from spambots. You need JavaScript enabled to view it


Kwality Photonics  P Ltd

ISO9001-2008, India's Pioneer Manufacturer of LED Segments & LEDs since 25 years.

29AB, Electronic Complex, Kushaiguda, HYDERABAD 500062


DID YOU TRY INDIA's HOTTEST  - UVC 275nm 15mW 0.6W for GERMICIDAL APPLICATION -130% effective than UV Tubes

Last Updated on Tuesday, 30 June 2020 15:35

Contact Us

Plot 29A&B, Road11, Electronic Complex, Kushaiguda, Hyderabad 500062 Telangana India ( near TSIIC canteen & Accord)

Kwality Segment  Digits (Kwality Photonics) : +91 7207074339 ( landline )

Kwality SMD LEDs ( Kwality Photonics ) +91  7981230551. 9000081171.  8179409843.

Through-Hole LEDs (Kwality Electronics) - Murthy : +91(40)-27133179.