Question

What type of semiconductor will form, when boron impurity is doped in a crystal lattice of Silicon?

• A. p-type semiconductor
• B. n-type semiconductor
• C. Instrinsic semiconductor
• D. None of these

Answer 1

The correct option is A p-type semiconductor

When small amount of trivalent element ( boron) is added, all three valence electrons form bond with three silicon atoms and a positive hole is created. The positive hole is free to move and can enhance the electrical conductivity of silicon through positive hole conduction mechanism.
Such semiconductors are called as p-type semiconductor.
Phosphrous and arsenic are pentavalent, when these impurities are added to silicon it creates extra electrons and cause n-type semiconductors.