when light falls on the extrinsic semiconductor, % increase in minority carriers are higher than majority charge carriers, please explain why ?
Dear Narinder,
this is quite easy to understand. Here just the main message:
E.g. you take an n-type doped Si and you are at a temperature where all donors are ionized. Then your majority charge carriers
are electrons with an electron density of about the concentration of your donor atoms.
If you now shine light with an energy larger than the bandgap energy of Si, you excite electrons from the valence to the conduction band, leaving the same amount of holes (minority charge carriers) in the valence band. If you look now at the concentrations of majority and minority charge carrriers, you see that to the extremely high amount of electrons from before only some additional ones are generated, while the same amount of generated holes is a drastical increase compared to the hole concentration from before illuminating.
For further insight you shall consult a regular textbook on semiconductor physics.
Best regards,
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