What happens to the conductivity of photoconductive material when light shines on it?

It increases.

Some materials conduct electricity better when exposed to light waves (particular frequencies of electromagnetic radiation).

At specific rates, they absorb the radiation not only from light, but from other frequencies such as gamma, infrared, UV's, etc.

The waves add energy to material's electrons, causing a numerical increase in free electrons and also of holes, which facilitate electron movement--increased conductivity

In electronics, these photosensitive materials act as resistors whose rating depends on the introduction of radiation waves.

The photosensitive devices can be classified as photo:

• Voltaic--solar cells, producing electricity
• Conductive--light dependent resistors LDR, light sensors
• Junction--semiconductors, transistors
• Emissive--increase conductivity, free electron movement

See Wikipedia's article on Photoconductivity

For more information, please see Electronics Tutorials site for the article on Light Sensors

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What is the photoconductive effect?

The increased conductivity of an illuminated semiconductor junction.

These are called "PN-Junction" light sensors/detectors. They are made with silicon semiconductor material as they are sensitive to light waves radiation and infrared light radiation

Some materials conduct electricity better when exposed to light waves (particular frequencies of electromagnetic radiation).

At specific rates, they absorb the radiation not only from light, but from other frequencies such as gamma, infrared, UV's, etc.

The waves add energy to material's electrons, causing a numerical increase in free electrons and also of holes, which facilitate electron movement--increased conductivity

In electronics, these photosensitive materials act as resistors whose rating depends on the introduction of radiation waves.

The photosensitive devices can be classified as photo:

• Voltaic--solar cells, producing electricity
• Conductive--light dependent resistors LDR, light sensors
• Junction--semiconductors, transistors
• Emissive--increase conductivity, free electron movement

See Wikipedia's article on Photoconductivity

For more information, please see Electronics Tutorials site for the article on Light Sensors

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What does the photoconductive effect in crystalline solids produce a noticeable change in?

The resistance of the solid.

For explanation here, please see the Iopscience Iop Org site for the article on Morphology Dependent Conductivity and Photoconductivity of Ionic Porphyrin Crystalline Assemblies,

containing the report from the Electrochemical Society's ECS Journal of Solid State Science and Technology, the 9-page pdf report on Morphology Dependent Conductivity and Photoconductivity of Ionic Porphyrin Crystalline Assemblies

Some materials conduct electricity better when exposed to light waves (particular frequencies of electromagnetic radiation).

At specific rates, they absorb the radiation not only from light, but from other frequencies such as gamma, infrared, UV's, etc.

The waves add energy to material's electrons, causing a numerical increase in free electrons and also of holes, which facilitate electron movement--increased conductivity

In electronics, these photosensitive materials act as resistors whose rating depends on the introduction of radiation waves.

The photosensitive devices can be classified as photo:

• Voltaic--solar cells, producing electricity
• Conductive--light dependent resistors LDR, light sensors
• Junction--semiconductors, transistors
• Emissive--increase conductivity, free electron movement

See Wikipedia's article on Photoconductivity

For more information, please see Electronics Tutorials site for the article on Light Sensors

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What is the description of an optoisolator?

An LED and a photosensitive device.

From Tech Target site's article on optoisolator (optical coupler or optocoupler), by Katie Terrell Hanna:

"An optoisolator (also known as an optical coupler, photocoupler, optocoupler) is a semiconductor device that transfers an electrical signal between isolated circuits using light.

These electronic components are used in a wide variety of communications and monitoring systems that use electrical isolation to prevent high voltage emitters from affecting lower power circuitry receiving a signal."

Also, for more information, please see Wikipedia's article on Opto-isolator

And, see Electronics Tutorials site for the article Optocoupler Tutorial

Some materials conduct electricity better when exposed to light waves (particular frequencies of electromagnetic radiation).

At specific rates, they absorb the radiation not only from light, but from other frequencies such as gamma, infrared, UV's, etc.

The waves add energy to material's electrons, causing a numerical increase in free electrons and also of holes, which facilitate electron movement--increased conductivity

In electronics, these photosensitive materials act as resistors whose rating depends on the introduction of radiation waves.

The photosensitive devices can be classified as photo:

• Voltaic--solar cells, producing electricity
• Conductive--light dependent resistors LDR, light sensors
• Junction--semiconductors, transistors
• Emissive--increase conductivity, free electron movement

See Wikipedia's article on Photoconductivity

For more information, please see Electronics Tutorials site for the article on Light Sensors

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What happens to the conductivity of a photosensitive semiconductor junction when it is illuminated?

The junction resistance decreases.

From erik walter.:

Standard semiconductors use voltage at the base to control the conductivity of the junction a photosensitive semiconductor uses light instead.

As the light increases the junction resistance decreases therefore increasing the conductivity.

Some materials conduct electricity better when exposed to light waves (particular frequencies of electromagnetic radiation).

At specific rates, they absorb the radiation not only from light, but from other frequencies such as gamma, infrared, UV's, etc.

The waves add energy to material's electrons, causing a numerical increase in free electrons and also of holes, which facilitate electron movement--increased conductivity

In electronics, these photosensitive materials act as resistors whose rating depends on the introduction of radiation waves.

The photosensitive devices can be classified as photo:

• Voltaic--solar cells, producing electricity
• Conductive--light dependent resistors LDR, light sensors
• Junction--semiconductors, transistors
• Emissive--increase conductivity, free electron movement

See Wikipedia's article on Photoconductivity

For more information, please see Electronics Tutorials site for the article on Light Sensors

Last edited by markadlerdallas. Register to edit

Tags: none

What is the description of an optocoupler?

An LED and a photosensitive device.

From Tech Target site's article on optoisolator (optical coupler or optocoupler), by Katie Terrell Hanna:

"An optoisolator (also known as an optical coupler, photocoupler, optocoupler) is a semiconductor device that transfers an electrical signal between isolated circuits using light.

These electronic components are used in a wide variety of communications and monitoring systems that use electrical isolation to prevent high voltage emitters from affecting lower power circuitry receiving a signal."

Also, for more information, please see Wikipedia's article on Opto-isolator

And, see Electronics Tutorials site for the article Optocoupler Tutorial

Some materials conduct electricity better when exposed to light waves (particular frequencies of electromagnetic radiation).

At specific rates, they absorb the radiation not only from light, but from other frequencies such as gamma, infrared, UV's, etc.

The waves add energy to material's electrons, causing a numerical increase in free electrons and also of holes, which facilitate electron movement--increased conductivity

In electronics, these photosensitive materials act as resistors whose rating depends on the introduction of radiation waves.

The photosensitive devices can be classified as photo:

• Voltaic--solar cells, producing electricity
• Conductive--light dependent resistors LDR, light sensors
• Junction--semiconductors, transistors
• Emissive--increase conductivity, free electron movement

See Wikipedia's article on Photoconductivity

For more information, please see Electronics Tutorials site for the article on Light Sensors

Last edited by markadlerdallas. Register to edit

Tags: none