How Does Wavelength Affect Light Penetration in Photodetectors?

[RajChakrabrty]

Homework Statement

what is the physical significance of wavelength (not the definition)?

Homework Equations

suppose,
in photodetectors (like avalanche or p-i-n photo diodes) incident light having more wavelength,
penetrates more in the diode (particularly in depletion region : )

so, how this more penetration for higher wavelength can be described?

The Attempt at a Solution

 

[nickjer]

How is energy of light related to wavelength? And what is the relation between this energy and the bandgap of the semiconductor?

 

[RajChakrabrty]

light enrgy is related to its own wavelength.
Eg=hc/lambda.
lambda=wavelength.

but for more wavelength,
incident light penetrates the photo-detectors more in their depletion region.
my question is how this more penetration for more wavelength can be described,
the physical significance of it.

 

[nickjer]

Well penetration means it isn't absorbed. So you have to think of what can cause absorption in a semiconductor and how does this relate to the energy of the light.

 

[Redbelly98]

Homework Statement

what is the physical significance of wavelength (not the definition)?

A light wave can be thought of as a repeating pattern of electric and magnetic fields, propagating through space. The wavelength is related to that pattern.

 

[RajChakrabrty]

A light wave can be thought of as a repeating pattern of electric and magnetic fields, propagating through space. The wavelength is related to that pattern.

so, what can be realized by wavelength, from this thought?
what is the difference for longer wavelength?

 

[Redbelly98]

Have you been taught about sine and cosine functions in school, and the period of a sine or cosine graph? Those are the concepts that come into play here.

Since this appears to be a homework assignment, we don't just hand out answers. That's why I'm providing conceptual hints to help you think about what is going on.

 

[RajChakrabrty]

Have you been taught about sine and cosine functions in school, and the period of a sine or cosine graph? Those are the concepts that come into play here.

Since this appears to be a homework assignment, we don't just hand out answers. That's why I'm providing conceptual hints to help you think about what is going on.

having sine and cosine graph concept and period ...

why light having more wavelength penetrates more?
like why infrared is used for shorter distance than bluetooth?

because of shorter wavelength of infrared.
but,
why short wavelength light is unable to penetrate more?
this is my question, you can say.