Question 157: Semiconductors and Logic Gates

Question

Mobility of electrons in a semiconductor is defined as the ratio of their drift velocity to the applied electric field. If, for an n-type semiconductor, the density of electrons is 10
19
m
$$-$$3
and their mobility is 1.6 m
2
/(V.s) then the resistivity of the semiconductor (since it is an n-type semiconductor contribution of holes is ignored) is close to :

Accepted Answer

For semiconductor,
Conductivity, $$\sigma $$ = n
e
q $$\mu $$
e
+ n
h
q $$\mu $$
h
given that semiconductor is n-type. So contribution of holes is ignored.
$$ 	herefore $$   n
h
q $$\mu $$
h
= 0
$$ 	herefore $$   $$\sigma $$ = n
e
q $$\mu $$
e
Resistivity, $$ho $$ = $${1 \over \sigma }$$
=  $${1 \over {{n_e}q{\mu _e}}}$$
=  $${1 \over {{{10}^{19}} 	imes 1.6 	imes {{10}^{ - 19}} 	imes 1.6}}$$
=  $${1 \over {1.6 	imes 1.6}}$$
=  0.4 $$\Omega $$ m

Answer

$$2\,\Omega $$m

Answer

4$$\,\Omega $$m

Answer

0.4 $$\,\Omega $$m

Answer

0.2 $$\,\Omega $$m

Semiconductors and Logic Gates

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