The various factors like doping element, nature of doping element, the majority and minority carriers in the p-type and n-type semiconductor. The density of electrons and holes, energy level and Fermi level, the direction of movement of majority carriers, etc. are considered in explaining the difference between p-type and n-type semiconductors.
The difference between a p-type semiconductor and an n-type semiconductor is given below in the tabulated form.
|BASIS OF DIFFERENCE
|p TYPE SEMICONDUCTOR
|n TYPE SEMICONDUCTOR
|Group of Doping Element
|In P type semiconductor III group element is added as doping element.
|In n type semiconductor V group element is added as doping element.
|Nature of Doping Element
|Impurity added creates vacancy of electrons (holes) called as Acceptor Atom.
|Impurity added provides extra electrons and is known as Donor Atom.
|Type of impurity added
|Trivalent impurity like Al, Ga, In etc. are added.
|Pentavalent impurity like P, As, Sb, Bi etc. are added.
|Holes are majority carriers
|Electrons are majority carriers
|Electrons are minority carriers
|Holes are minority carriers
|Density of Electrons and Holes
|The hole density is much greater than the electron density.
nh >> ne
|The electron density is much greater than the hole density.
ne >> nh
|The acceptor energy level is close to the valence band and away from the conduction band.
|The donor energy level is close to the conduction band and away from the valence band.
|Fermi level lies between acceptor energy level and the valence band.
|Fermi level lies between donor energy level and the conduction band.
|Movement of Majority carriers
|Majority carriers move from higher to lower potential.
|Majority carriers move from lower to higher potential.
The p-type semiconductor is formed when the Trivalent impurity is added to the pure semiconductor. Similarly, when a Pentavalent impurity is added to the pure semiconductor n-type semiconductor is obtained.
Difference Between p-Type and n-Type Semiconductor
- In a p-type semiconductor, the III group element of the periodic table is added as a doping element, whereas in n-type the V group element is the doping element.
- Trivalent impurity like Aluminium, Gallium, and Indium is added in the p-type semiconductor, while in the n-type semiconductor Pentavalent impurity like Arsenic, Antimony, Phosphorus, Bismuth, etc. are added.
- The impurity added in p-type semiconductor provides extra holes known as Acceptor atom, whereas in n-type semiconductor impurity provides extra electrons and termed as Donor atom.
- In a p-type semiconductor, the majority carriers are holes, and the minority carriers are electrons. In the n-type semiconductor, electrons are majority carriers, and holes are minority carriers.
- The electron density is much greater than the hole density in the n-type semiconductor denoted as ne >> nh whereas, in p-type semiconductor the hole density is much greater than the electron density nh >> ne.
- In an n-type semiconductor, the donor energy level is close to the conduction band and away from the valence band. In the p-type semiconductor, the acceptor energy level is close to the valence band and away from the conduction band.
- The Fermi level of the n-type semiconductor lies between the donor energy level and the conduction band while the Fermi level of the p-type semiconductor lies between the acceptor energy level and the valence band.
- Majority carriers move from higher to lower potential in p-type whereas, in n-type, the majority carriers move from lower to higher potential.
In this way p-type and n-type semiconductors are differentiated.