What happens when silicon is doped with boron and phosphorus?

Boron, arsenic, phosphorus, and occasionally gallium are used to dope silicon. Doping with Group III elements, which are missing the fourth valence electron, creates “broken bonds” (holes) in the silicon lattice that are free to move. The result is an electrically conductive p-type semiconductor.

What type of semiconductor is obtained when silicon is doped with boron and phosphorus?

(a) When silicon is doped with boron, a p-type semiconductor is obtained.

When boron is doped with silicon the type of semiconductor is?

p-type semiconductor
A p-type semiconductor is an intrinsic semiconductor doped with boron (B) or indium (In). Silicon of Group IV has four valence electrons and boron of Group III has three valence electrons.

What is meant by the term doped in phosphorus doped and boron doped?

Doping means the introduction of impurities into a semiconductor crystal to the defined modification of conductivity. Two of the most important materials silicon can be doped with, are boron (3 valence electrons = 3-valent) and phosphorus (5 valence electrons = 5-valent).

What type of semiconductor is obtained when silicon is doped with?

Detailed Solution

N-type Semiconductor	P-type Semiconductor
The pentavalent impurities provide extra electrons and are termed donor atoms.	The trivalent impurities added provides extra holes known as the acceptor atom.

What happen when boron doped with silicon?

These electrons are known as valence electrons. When silicon is doped with boron, the three electrons of boron bond with the three electrons of silicon. To bond with this one free electron of silicon one electron from the neighbouring silicon atom is taken. This creates a hole or vacancy in the conductor.

Why does silicon Si doped with gallium GA have higher electrical conductivity than Si alone?

Doping silicon with gallium produces a p-type semiconductor. Because gallium has fewer valence electrons than silicon, holes (unfilled energy levels) at energies in the previously filled molecular orbitals are created, which induces greater electron movement (greater conductivity)

What elements can be doped with silicon?

Doping. Two of the most important materials silicon can be doped with, are boron (3 valence electrons = 3-valent) and phosphorus (5 valence electrons = 5-valent). Other materials are aluminum, indium (3-valent) and arsenic, antimony (5-valent).

What happens when phosphorus is doped with intrinsic silicon?

When it is doped with an intrinsic silicon, four of the phosphorus electrons form covalent bonds with four neighbouring silicon atoms. The fifth electron have no chance of forming a covalent bond so that it is loosely bounded and is far away from nucleus.

Why is phosphorus a semiconductor at room temperature?

Phosphorus creates an energy state 0.045eV below the conduction band. At room temperature, nearly all Phosphorus atoms will donate an electron to the conduction band. Therefore, doping with phosphorus will create an n-type semiconductor.

What is the electronic band structure in doped semiconductors?

4. Electronic band structure in doped semiconductors. By the introduction of a dopant with five outer electrons, in n-doped semiconductors there is an electron in the crystal which is not bound and therefore can be moved with relatively little energy into the conduction band.