A donor impurity is basically a type of dopant that has five electrons in its outer shell. When we add it to a semiconductor, its main job is to boost conductivity. It does this by donating one of those extra electrons to a nearby atom. This is why we call it a “donor”—it donates electrons. When we have this extra negative charge, it helps form what’s known as the n-type region, turning the semiconductor into an n-type material. So, whenever we want to create n-type semiconductors, we rely on these donor impurities.
Definition of Acceptor Impurity
An acceptor impurity is a dopant that contains 3 electrons in its valence shell. When added to a semiconductor to enhance its conductivity, it can accept an electron from a neighboring atom, as it has a vacancy for an electron. This characteristic of accepting electrons gives it the name ‘acceptor.’ The presence of the extra positive charge leads to the formation of the p-type region, making the semiconductor p-type. Acceptor impurities are used to create p-type semiconductors.
Comparison of Donor and Acceptor Impurities
Here is the comparison chart in active voice:
| Basis for Comparison | Donor Impurities | Acceptor Impurities |
|---|---|---|
| Basic | Donor impurities are impurities that increase the conductivity by donating a charge. | Acceptor impurities are impurities that accept the charge to increase conductivity. |
| Also Referred as | Donor impurities are also known as pentavalent impurities. | Acceptor impurities are also known as trivalent impurities. |
| Number of Valence Electrons | Donor impurities have 5 valence electrons. | Acceptor impurities have 3 valence electrons. |
| Forms | Donor impurities form n-type semiconductors. | Acceptor impurities form p-type semiconductors. |
| Group Position in Periodic Table | Donor impurities belong to Group V of the periodic table. | Acceptor impurities belong to Group III of the periodic table. |
| Examples | Examples of donor impurities are Phosphorus and Bismuth. | Examples of acceptor impurities are Aluminium and Boron. |
In summary, donor impurities, also called pentavalent impurities, have 5 valence electrons and form n-type semiconductors. On the other hand, acceptor impurities, also known as trivalent impurities, have 3 valence electrons and form p-type semiconductors.