# What makes of a current in solidstate/semiconductor physics?

If there is some incoming light that has hit electrons of a N-type doped silicon and broke loose these electrons from their covalent bounds and excited them to the conduction band and also excited the electrons in the donor energy level to the conduction band as well, here we know that,

the Majority charge carriers are electrons, so if we apply an external voltage and drive holes(minority charge carriers) and electrons(majority charge carriers) apart and measure the current, does the measured value of current give the value caused by only electrons flowing(majority charge carriers) or the value caused by only holes flowing(minority charge carriers) or value caused by both(amount of electrons(majority) + holes(minority)) of them ??

I am confused.

• All moving charge carriers contribute to the measured current. Jun 15, 2021 at 11:23

However, it is often the case that the vast majority of the current is from only a single carrier type. If you have a block of semiconductor and apply a voltage across it you have a resistor. If it is doped such that $$n\gg p$$ then you can ignore the contribution of holes and get a correct answer to a few decimal places.
It is easy to dope silicon such that $$n>10^8p$$. In this case unless you care about 0.000001% precision, you can safely ignore holes in the example I gave above.