How does the reflectivity of silicon change with current?

[shantanuphadke]

Hello I am trying to fabricate a Si reflecting solar cell.

When a Solar cell is exposed to radiation and connected to external circuit, the current will start to flow through the circuit. So I want to know how does the Reflectivity of silicon change with the current( or conductance).[ Initially when solar cell is irradiated but not connected to circuit, the current is zero. when connected to external circuit, current rises. So how does the reflectivity change with change in current]

If the question is not clear please let me know

Thank you in advance for your help.

 

[M Quack]

Reflectivity does not really change a lot whether the current is flowing or not. Light produces electron-hole pairs in the silicon. When the cell is connected there are collected at opposite electrodes and thus generates a current.

When the cell is not connected no current flows so eventually an electric field builds up that stops the electrons and holes from being collected at the electrodes. Instead they just recombine within the silicon, producing heat.

All this has very little to do with the reflectivity, therefore the reflectivity does not change.

 

[shantanuphadke]

I was thinking in this way,
Transmission through the back silvered black silvered solar cell is zero.
So Energy is either absorbed or reflected.
Does the absorption remain the same?

Thank you!

 

[M Quack]

Yes, absorption remains the same due to the short life time of the electron hole pair.

In other materials with a very long life time you can saturate the absorption. This can happen in certain lasers

http://www.orc.soton.ac.uk/publications/theses/1400T_clb/clb-5.pdf