Definition of Donor Impurity
A donor impurity is a dopant that contains 5 electrons in its valence shell. When added to a semiconductor to increase its conductivity, it can donate an extra electron from its valence shell to a neighboring atom. This ability to donate electrons gives it the name ‘donor.’ The presence of the extra negative charge contributes to the formation of the n-type region, making the semiconductor n-type. Donor impurities are used to create n-type semiconductors.
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.