In last post HALL EFFECT IN n TYPE SEMICONDUCTOR and HALL EFFECT IN p-TYPE SEMICONDUCTORS ,we have studied HALL effect in n-type and p-type semiconductors
In this article we will familiar with hall effect in Intrinsic semiconductors
Since mobility of electrons is higher than that of mobility of holes so more number of electron will accumulate at surface (2) in compare to that of number of holes ,
NOTE: So behavior of HALL effect in intrinsic Semiconductors is same as in case of HALL effect in n-type semiconductors
HALL COEFFICIENT ():
= -(
) HALL coefficient is negative for n-type semiconductors , metals , intrinsic semiconductors
= (
) HALL coefficient is positive for p-type semiconductors
APPLICATION OF HALL EFFECT:
(1) It can determine type of semiconductor materials , whether it is p-type or n-type semiconductor materials
(2) If HALL coefficient() for a semiconductor material is given , by use of this we can calculate the concentration of charge carriers in semiconductor material
= -(
)
= concentration of charge carriers =-(1/
)
(3) With the help of HALL coefficient ,we can determine mobility
of charge carriers ( mobility of electron and holes) in a semiconductor material
we know that
= (
) (1)
(2)
from equation (1) and (2)
=
(3)
by use of equation (3) one can calculate mobility of electrons , if conductivity due to electrons (
) in semiconductors and Hall coefficients
is given
(4) Hall effect in semiconductor materials can used as multiplier , known as “HALL EFFECT MULTIPLIER”
we know that hall voltage =
let =
is first input to multiplier
=
let ∝
( since a magnetic field an be produced by current )
this will give = (
)
So output voltage( ) of multiplier is directly proportional to the product of these two input current
and
so outcomes of Hall effect can be used as multiplier
