Answer to Question #82822 in Electric Circuits for Kainat shah

Question

What is the reason fir adding a donor element to a semiconductor?

Answer 1

Semiconductors are usually made of chemical elements that belong to the IV group. It means that these elements have 4 valence (free and ready to make bonds) electrons. To make it a real semiconductor we can add an acceptor of donor element. Donor elements have 5 valence electrons, which form 4 bonds with 4 valence electrons of main element and one electron of donor is weakly bonded. One “liberated” electron thus becomes a charge carrier and can carry a current. This is how n-type semiconductors are made.