Question

What type of semiconductor is obtained when $Si$ is doped with $As$?

Answer 1

Arsenic (As) has five and Silicon (Si) has four valence electrons in their respective outermost shell. When Si is doped with As, four electron of As forms covalent bond with the four electrons of Si while one electron remains free for conduction. N- type of semiconductor is denoted by positive ion and free electron. Therefore, n-type of semiconductor is formed when Si is doped with As or any other pentavalent atom.