N type semiconductors have excess electrons or holes ?

Question

Answer

Electrons are the majority carriers of n typ semiconductor whereas holes are the majority carriers of p type semiconductor.

Answer

Electrons are the majority carriers of n type semiconductor whereas holes are the majority carriers of p type semiconductor.

Answer

Electrons

Answer

N-type semiconductors have excess electrons.

N-type semiconductors are formed by adding impurities to the pure semiconductor material, usually by doping with elements from Group V of the periodic table, such as phosphorus or arsenic. These impurities are called donor impurities because they donate extra electrons to the semiconductor crystal structure.

Donor impurities
- Donor impurities have five valence electrons, one more than the four valence electrons of the atoms in the pure semiconductor material (Group IV elements like silicon or germanium).
- When a donor impurity atom is incorporated into the crystal lattice of the semiconductor material, the extra electron becomes loosely bound and can move freely within the crystal structure.
- At room temperature, some of the donor impurity atoms ionize, releasing the extra electron into the conduction band of the semiconductor.

Excess electrons
- The presence of these extra electrons in the conduction band gives rise to an excess of negative charge carriers, known as free electrons.
- These free electrons are responsible for the electrical conductivity of the N-type semiconductor.
- Due to thermal energy, the free electrons move randomly within the crystal lattice, creating an electron current when an electric field is applied.

Effect on conductivity
- The presence of excess electrons in the N-type semiconductor increases its conductivity.
- The free electrons can easily move through the crystal lattice, contributing to the flow of electric current.
- The higher the concentration of donor impurities, the greater the number of excess electrons and thus the higher the conductivity of the N-type semiconductor.

Conclusion
In summary, N-type semiconductors have excess electrons due to the incorporation of donor impurities from Group V elements. These excess electrons increase the conductivity of the semiconductor and are responsible for its electrical properties.

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