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What are the sources of white light?

What are the sources of white light?

Sources of White Light The Sun is the most significant source of white light in our solar system. As for artificial, white LEDs and fluorescent light bulbs can produce white light. Some light bulbs, such as incandescent lamps, do not contain white light.

Which of the following is an example of a white light source?

For example, the sun and other stars are sources of white light. The sun is the most obvious source of white light in our solar system. As for artificial sources, fluorescent light bulbs and white LEDs produce white light. Other light bulbs, like the incandescent lamp, do not produce white light.

Can a semiconductor emit white light?

A unique type of inorganic−organic hybrid semiconductor bulk material is capable of emitting direct white light. Semiconductor bulk materials that have good transport properties and can convert electricity directly to white light are most desirable.

Is it possible to make a white LED from a single semiconductor?

The tiny red and green indicator lights on computers and other devices are so familiar, the fact that the first LEDs were limited to a dim red output is probably not widely recognized. More important, the discovery made it technically feasible to produce white light from the tiny semiconductor devices.

How many wavelengths are there in white light?

The Wavelength of White Light White light is made up of seven colors viz: violet, green, indigo, orange, blue, yellow, and red. Here, the wavelength of red is 400 mm, and that of violet is 700 mm.

Does white light have a wavelength?

White light is actually made of all of the colours of the rainbow because it contains all wavelengths, and it is described as polychromatic light. Light from a torch or the Sun is a good example of this. Light from a laser is monochromatic, which means it only produces one colour.

Do silicon diodes emit light?

Because silicon doesn’t like to emit light. In silicon, electrons have to emit a photon and a sound vibration (a phonon) at the same time to reach the valence band. Instead, the electron typically finds a way to lose the energy without emitting a photon, so no light comes out.

Can germanium be used as an efficient light emitting source?

Light Emitting Diode Structure Silicon and germanium are not suitable because those junctions produce heat and no appreciable IR or visible light. An exposed semiconductor surface can then emit light.

How do LEDs produce white light?

Phosphor-converted LEDs generate white light by blending light of various colors. In one commercial design (left), light from a blue-emitting LED excites a yellow phosphor. Blue and yellow combine to make white light.

How do light emitting diodes produce light?

A diode, as in LED (Light emitting Diode), is a combination of different materials that does this and as a result light is emitted. As electricity passes through these materials the electrons in the compound become excited and emit photons of light.

Does white light has a wavelength?

What is white light give a source of white light Class 10?

White light is a mixture of the spectrum of visible wavelengths. It is a part of electro magnetic spectrum. Visible light or white light comes above the infrared rays. Sun is the source of white light.

How is white light produced?

Other possible approaches to producing white light, utilizing a single device, are based on phosphor or dye wavelength converters or semiconductor wavelength converters.

What is a white LED?

The concept of a white LED is particularly attractive for general illumination, due to the reliability of solid-state devices, and the potential for delivering very high luminous efficiency compared to conventional incandescent and fluorescent sources.

How do white light diodes work?

Most white-light diodes employ a semiconductor chip emitting at a short wavelength (blue, violet or ultraviolet) and a wavelength converter, which absorbs light from the diode and undergoes secondary emission at a longer wavelength. Such diodes, therefore, emit light of two or more wavelengths, that when combined, appear as white.

What is the wavelength of light emitted from a light emitting diode?

The first commercial light emitting diode, developed in the 1960s, utilized the primary constituents gallium, arsenic, and phosphorus to produce red light (655-nanometer wavelength). An additional red light-emitting material, gallium phosphide, was later used to produce diodes emitting 700-nanometer light.

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