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Explain the generation and recombination of electrons and holes in semiconductor?
Wiki User
∙ 11y ago
Simply, the two fundamental laws are energy conservation and and momentum conservation.
Wiki User
∙ 11y ago
Wiki User
∙ 11y agohdffd
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How are P and N type semiconductors formed?
FORMATION OF P-TYPE SEMI CONDUCTOR A P - type semiconductor is formed when a small amount of trivalent impurity is added to pure Germenium or silicon atom crystal. The addition of trivalent impurity produces a large no. of holes to the host crystals. To explain the formation of P - type semiconductor, let usintroduce a trivalent impurity into the lattice of a pure silicon crystal. The trivalent atom has 3 valanceelectrons and form covalent bonds with neighbouring atoms. The 4th bond is incomplete . the trivalent atom then attracts an electron from an adjacent atom there bycompleting the 4th bond and forming a hole in the adjacent atom. Since a trivalent impurity atom provides 1 hole, an enormous increase occurs in the number of holes. The impure crystals so obtained is called P - type semiconductor where P represents the positive charge on hole. Thus the majority carrier in a P - type semiconductor are holes. Freeelectrons are also present in the P - type semiconductor. These are thermally generated and since they relatively few, they are called minority carriers. The trivalent impurity atoms are called acceptors because each accepts an electron when the atom is introduced into the host crystal.FORMATION OF N TYPE SEMI CONDUCTORAn N - type semiconductor is formed when a small amount of pentavalent impurity is added to a pure Germenium or Silicon crystal. The addition of pentavalent impurity produces a large no. of free electrons in the host crystal.To explain the formation of N - type semiconductor, let us introduce a pentavalent impurity atom into the lattice of pure silicon crystal. The pentavalent atom has 5 valance electrons, but only 4 form covalent bonds with the neighbouring atoms. The 5th electron finds no place in the covalent bonding so becomes free. Since an impurity atom provides one free electron, an enormous increase occurs in the no. of free electrons. The impure semiconductor so obtained is then called as N - type semiconductor where N represents negative charge on an electron. Thus the majority carrier in N - type semiconductor are free electrons. Holes are also present in the N - type semiconductor. These are thermally generated and since they are relatively few, they are called minority carrier.The pentavalent impurity atom are called donour because each donate a free electron to the host crystal.
Explain how you know that it is an electric field not electrons that moves rapidly through a circuit?
Electrons in an active circuit either drift slowly, or just jiggle back and forth in one place.
Distinguish between valence and conduction electron hence explain the mechanism of electrons heat and heat transfer in conduction?
Why is conduction important?
Explain the difference between electronics and electricity?
Electronics is a science dealing with electrons emission electrical is a science dealing with electron flow
Why is the mobility of electrons greater than the mobility of holes?
In an intrinsic semiconductor, a few electrons get thermally excited and break from their valence bond to become a free electron. This leaves behind a vacancy in its place called 'hole'. In a P-type semiconductor, B with 3 electrons replaces a Si atom with 4 electrons in the lattice. 3 covalent bonds are formed by B with 3 neighbouring Si. But there is a deficiency of one electron in B for bonding with the 4th Si. This deficiency/vacancy is called a hole. When an electric potential difference is present, the electrons from adjacent valence bond moves into the vacancy near it while moving along the potential. The following represents the movement of valence electron. Terminology: * represents valence electron _ represents hole A is -ve and B is +ve. ..I A * * * _ * * * B .II A * * _ * * * * B III A * _ * * * * * B .IV A _ * * * * * * B I- Hole is at the 4th position. II- At first, the 3rd electron from left shifts right to fill the vacancy and leaves behind a vacancy in its place. The vacancy is at the 3rd position. III- Next, the 2nd electron from left has shifted to the 3rd place and filled up that vacancy but leaves a vacancy at its place. The vacancy is at 2nd position. IV- Now, the 1st electron from left moves to occupy the vacancy at the 2nd position creating another vacancy in its own place. The vacancy is at 1st position. As the electrons moved right, the vacancy moved left. The vacancy is called a hole (just a shorter name for convenience). The movement of holes is really the movement of electron in the valence band. Therefore, the mobility of a hole is indirectly the mobility of valence electrons. Mobility is the velocity acquired per unit electric field. In the intrinsic and N type semiconductors, many free electrons are present i.e. electrons in conduction band which are free to move in the crystal as against valence electrons which can only move in the lattice points. When an electric field is applied, both the valence electrons and the free electrons move in the same direction. The hole direction is opposite to that of valence electron but the mobility is the same, as explained earlier. Even for the same electric field, valence electrons cannot move as freely as the free electrons because its movement is restricted. Therefore, the velocity of valence electrons is less compared to free electrons. In other words, the velocity of holes is less compared to free electrons. This means mobility is also less for a hole compared to free electron. Thus, mobility of a free-electron (often abbreviated as 'electron') is greater than that of a hole (indirectly referring to valence electron).
What are semiconductor memory and what are its type?
what is a semiconductor material? what are its main types, explain each type
How does band theory explain to construct semiconductor?
pay $500000000000000 if you want to know the answer
What is hall effect explain briefiy?
Deflection of moving carriers in a semiconductor perpendicular to a magnetic field.
What does the model of a sea of electrons help explain?
It helps explain metallic bonds.
Explain MOSFET elaborately?
MOSFET = metal-oxide semiconductor field effect transistor That in itself is quite elaborate.
Can electrons lose energy at ground state explain?
No. At ground state, the electrons are at their lowest energy.
How do you explain the generation of computer with a diagram?
A diagram that explains the generation of the computer can be found on the Scribd website. First generation computers used vacuum tubes.
How can explain the chapter a nations strength in own words?
Generation
Explain the concept of character generation in computer graphics?
L
Explain of where electrons might be found in atom?
firemen
When bromine reacts with other elements it gains electrons gaining electrons does not effect the mass of the bromine atoms explain why?
electrons have no mass
Explain how the properties of outer shell electrons affect metals?
Thrse electrons are involved in chemical reactions.
