Which one of the following describes the result of doping in semiconductors?
a. The impurity provudes additional energy states within the conduction band
b. More electron - hole pairs are introduced as a result of doping
c. For n - type semiconductor, the number of "holes" in the valence band remains small
d. For p - type semiconductor, there are more "holes" in the conduction band
e. None of the above
The Attempt at a Solution
Option (a) is wrong because energy states stay the same
Option (b) is wrong because doping only adds only electron or hole, not electron - hole pair
Option (c) I think is correct because for n - type the number of free electron in conduction band increases and number of hole in valence band stays the same
Option (d) I am not sure
Is my reasoning for (a) - (c) correct? And what about (d)?