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electrons have less effective size than that of holes(which actually are not real)...formula says
m(mobility)=drift velocity/electric field=et/m where t is relaxation time..
so mobility is inversely proportional to mass
hence e has more mobility.
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∙ 14y ago
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How do you Define the mobilty of charge carrier?
I am assuming the charge carries are electron and hole in an semiconductor. the mobility of charge carriers can be understood as the easy with which the carrier can move in a semiconductor. the mobility depends on many factors like the semiconductor material (because of the crystal structure), semiconductor specimen temperature, the effective mass of carrier, the applied electric field across the specimen. in general if we compare the mobility of electron with hole in a silicon semiconductor, the mobility values at room temperature is some thing around 1350 cm^2 per volt sec and 450 cm^2 per volt sec for electron and holes. that is mobility of electron is 2-3 time more than the holes in silicon.
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 is the major difference an NPN transistor and a PNP transistor?
The NPN transistor has its conduction curve where the base is more positive than the emitter, while the collector is also more positive than the emitter. The PNP transistor is exactly opposite, with its conduction curve where the base is less positive than the emitter, while the collector is also less positive than the emitter.
Why are germaninum diodes popular than silicon diodes?
because in Ge mobility of both electrons and holes is higher than the corresponding carriers in Si....and second reason -Ge can be refined and processed more easily..
Why NOR gates are preferred to NAND gates in program logic array systems when implemented as an ic?
electron mobility in nand 3 times more tat of nor gate. This makes nand faster than nor.
Which has greater mobility in intrinsic semiconductor Electrons or holes?
The mobility of electrons is always greater than holes. Only the number of electrons and holes would be same in an intrinsic semiconductor.
How do you Define the mobilty of charge carrier?
I am assuming the charge carries are electron and hole in an semiconductor. the mobility of charge carriers can be understood as the easy with which the carrier can move in a semiconductor. the mobility depends on many factors like the semiconductor material (because of the crystal structure), semiconductor specimen temperature, the effective mass of carrier, the applied electric field across the specimen. in general if we compare the mobility of electron with hole in a silicon semiconductor, the mobility values at room temperature is some thing around 1350 cm^2 per volt sec and 450 cm^2 per volt sec for electron and holes. that is mobility of electron is 2-3 time more than the holes in silicon.
Which subatomic particle has a greater mass a proton or an electron?
Proton has a greater mass than the electron.
Why mobility of electrone is larger than hole?
I may be wrong but...Holes don't exist - they are a nice way of describing electron movement but it's just a mathematical and descriptive term. Electrons do the actual moving Holes are just a way of talking baout electron movement.Electrons don't really exist either but that's getting a bit far into the physics.
Does an electron have a mass greater than a proton?
an electron has way less mass than a proton.
Which has a greater electron affinity fluorine or bromine?
Fluorine has greater electron affinity than bromine, or any other element.
Why the speed of electron beam is greater than the light speed in cathode ray oscilloscope?
Why is the speed of the electron beam greater than the speed of light in cathode ray oscilloscope.
Is the charge of an electron greater than the charge of a proton?
they are equal.
Why is the size of an ion greater than its parent atom?
Only the anion is greater than the atom because gained an electron.
Is the mass of an electron greater then the mass of a proton?
No. A proton is many times more massive than an electron.
Is the mass of a proton greater then the mass of a electron?
No. A proton is many times more massive than an electron.
Is The Mass Of An Electron Is Equal To The Mass Of A Neutrons?
No. The mass of a neutron is far, far, far greater than the mass of an electron. In fact, the mass of a neutron is approximately about 1840 times greater than the mass of an electron. The particle that has exactly the same mass as an electron is its antiparticle, the positron.
