Relationship between light wavelength, intensity and photons energy

[techguy]

Hi peeps,

i am having a project and i wish to clear some concept.

1. The shorter the wave length the higher the photon energy? Am i right?

2. The higher the intensity of light, the higher amount of photons exist in the light? Am i right?

3. So higher intensity plus short wave length will give a lot of overall energy in the light? Am i right?

Thanks!

 

[Hootenanny]

Hi peeps,

i am having a project and i wish to clear some concept.

1. The shorter the wave length the higher the photon energy? Am i right?

Correct

2. The higher the intensity of light, the higher amount of photons exist in the light? Am i right?

Spot on again

3. So higher intensity plus short wave length will give a lot of overall energy in the light? Am i right?

Yup.

 

[techguy]

Ok thanks! So here goes another question since my basic concept is correct...

so does that means that higher intensity plus short wavelength light, it will generate much more voltage and current as compared to same amount of intensity plus high wavelength light in photovoltaic cell?

 

[benj]

No this is not neccessarily true.

This is mostly down to a couple of reasons...

1. The general rule is one photon will be converted to one electron and the energy of this photon is not related to the energy the electron will deliver in terms of current and voltage (the exception to this case being down conversion solar cells where a high energy electron may be converted into two low energy electrons).

2. The solar cell will respond differently to different wavelengths of light. Higher energy photon does not neccessarily mean more likely to be converted into a photon.