How is light with different wavelengths produced in a LED?

The LED emits ultraviolet light to infrared light with various wavelengths. This emission wavelength is expressed by the following equation using the energy band gap (Eg) of compound semiconductor material. Larger Eg materials emit shorter wavelengths, and materials with smaller Eg emit longer wavelengths.

What is the mechanism of LED?

A light-emitting diode is a two-lead semiconductor light source. It is a p–n junction diode that emits light when activated. When a suitable voltage is applied to the leads, electrons are able to recombine with electron holes within the device, releasing energy in the form of photons.

What is the wavelength of light emitted from LED?

5.5. 3 Light-Emitting Diodes. LED is a semiconductor device that emits visible light when an electric current passes through it. The output from a LED can range from red (at a wavelength of approximately 700 nm) to blue-violet (about 400 nm).

What component of an LED determines the wavelength of the emitted photons?

bandgap
The separation of the bands (i.e. the bandgap) determines the energy of the photons (light particles) that are emitted by the LED. The photon energy determines the wavelength of the emitted light, and hence its color. Different semiconductor materials with different bandgaps produce different colors of light.

How does the wavelength of light emitted by LED vary with change in band gap energy of the semiconductor material?

The light emitting diodes are made of direct energy gap semiconductors. By increasing the temperature, the band gap energy decreases and the emitted wavelength increases. It follows that the peak wavelength shifts to longer wavelength and therefore this shift called the red shift.

How do you explain the working of LED by using the energy band diagram in forward biasing?

When Light Emitting Diode (LED) is forward biased, free electrons in the conduction band recombines with the holes in the valence band and releases energy in the form of light.

How do LEDs emit photons?

An LED bulb produces light by passing the electric current through a semiconducting material—the diode—which then emits photons (light) through the principle of electroluminescence.

On which factors does the light emitted by LED depends?

The colour of the light emitted by the LED depends on the wavelength of the light which in turn depends on the semiconductor material used in the diode while manufacturing LED. No other factor is responsible for the colour of light.

What do different LED light colors mean?

The lower the number, the more reddish or warmer the light. The higher the number, the more bluish or cooler the light. When we’re talking about the color of an LED light, especially in residential lighting, we’re really discussing two things… White lights and RGB (red, green, blue) lights.