Question

There is an increase in conductivity when silicon is doped with Phosphorus give reason?

Answer 1

There is an increase in conductivity when Silicon is doped with Phosphorus because : Si doped with P becomes N type semiconductor. ... In that four valence electrons will be used for bonding with Si and fifth electron serves to conduct electricity.

Answer 2

Hey !

This is due to the availability of delocalized electrons after doping Silicon with Phosphorous.

Explanation:

              Doping is the process of adding an impurity to an intrinsic semiconductor like silicon to increase its conductivity.

            Silicon belongs to group 14 and has 4 valence electrons. It is doped with an element like Phosphorous of Group 15 which has 5 valence electrons. 4 out of 5 electrons of Phosphorous form covalent bonds with the 4 electrons of Silicon. The 5th electrons becomes delocalized. Electrons that are free to move in the entire structure are called a delocalized electron.

                       These delocalized electrons increase the conductivity of the semiconductor. Such semiconductors are thus called n-type semiconductor.

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