As we know that conductivity of semicondutors can be increased or

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    Conductivity
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Discussion Overview

The discussion revolves around the photoconductivity of semiconductors, specifically addressing how their conductivity can be influenced by heat or photons. Participants explore the relationship between light wavelength and intensity in the context of using semiconductors as light meters.

Discussion Character

  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant claims that photoconductivity is dependent on the wavelength of light rather than its intensity, questioning how this aligns with the use of semiconductors as light meters.
  • Another participant challenges this claim, stating that opto semiconductors respond to variations in intensity and can be made to respond to different wavelengths through physical filters or material variations.
  • A different participant provides an example of infrared detectors from Hamamatsu, suggesting that different semiconductor materials exhibit varying spectral sensitivities and can respond to light intensity.
  • One participant references a book that states two lights of the same intensity but different wavelengths will produce different conductivities, implying a need for clarification on this point.
  • Another participant agrees with the previous point but adds that the sensitivity of the semiconductor material to different wavelengths must be considered.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between light intensity and wavelength in photoconductivity, with no consensus reached on the primary factors influencing semiconductor conductivity.

Contextual Notes

Some statements rely on specific semiconductor materials and their properties, which may not be universally applicable. The discussion also highlights potential limitations in understanding the nuances of photoconductivity.

lazyaditya
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As we know that conductivity of semicondutors can be increased or decreased by supplying heat or photons to the material.

Its said that photoconductivity of the semiconductors is dependent on the wavelength of the light and not on the intensity of the light then how are these used as the light meters
?
 
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lazyaditya said:
....Its said that photoconductivity of the semiconductors is dependent on the wavelength of the light and not on the intensity of the light then how are these used as the light meters ?

have you got a reliable reference for that ?

opto semiconductors I have worked with over the years respond nicely to variations in intensity.
you can get the semi to respond to different wavelengths either by the use of a physical filter in front of it or by the actual variations in the manufacture of the semiconductor material to make it more responsive to different wavelengths

cheers
Dave
 


lazyaditya said:
As we know that conductivity of semicondutors can be increased or decreased by supplying heat or photons to the material.

Its said that photoconductivity of the semiconductors is dependent on the wavelength of the light and not on the intensity of the light then how are these used as the light meters
?

You can find examples of how different materials respond to different wavelengths here:

"Hamamatsu manufactures various types of infrared detectors made from InSb, InAs, and InAsSb semiconductors. Different materials and types of detector (photodiode, photovoltaic or photoconductive) offer different spectral sensitivity within 1 µm and 6.5 µm."

http://sales.hamamatsu.com/en/produ.../compound-semiconductors/insb-inas-inassb.php

If you check the individual (pdf) data sheets you will see they also respond to the intensity of radiation. Many of them easily function as light intensity meters!
 


The thing is i read it in some book ! It was written that the two light of same intensity and different wavelengths will produce different conductivities.
 


lazyaditya said:
The thing is i read it in some book ! It was written that the two light of same intensity and different wavelengths will produce different conductivities.

as I hinted at above ... your comment would be correct if the particular semiconductor material used was more sensitive to wavelength A than it was to wavelength B

Dave
 


ok thnx :)
 

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