Physics for Electronics Engineering: Unit III: Semiconductors and Transport Physics
Carrier Transport in Semiconductor Mobility
In absence of an electrical field, the free electrons (electron gas) move in all directions in a random manner. They collide with other free electrons and positive ion core during the motion. This collision is known as elastic collision
CARRIER TRANSPORT IN SEMICONDUCTOR MOBILITY
In
absence of an electrical field, the free electrons (electron gas) move in all
directions in a random manner. They collide with other free electrons and
positive ion core during the motion. This collision is known as elastic
collision (Fig 3.12).
Fig. 3.12 Random motion of free
electrons in the absence of electric field (+ ve ion cores are not shown).
As
the motion is random, the resultant velocity in any particular direction is
zero.
When
an electrical field is applied in a semiconducting material, the free charge
carriers such as free electrons and holes attain drift velocity vd.
The
drift velocity attained by the carriers is proportional to the electrical field
strength E.
i.e.,
vd ∞ E
vd
= µ E
where
µ is a proportionality constant and it is known as the mobility of the charge
carrier.
This velocity vd is different for different semiconductors and for different types of charge carriers.
Physics for Electronics Engineering: Unit III: Semiconductors and Transport Physics : Tag: : - Carrier Transport in Semiconductor Mobility
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Physics for Electronics Engineering
PH3254 - Physics II - 2nd Semester - ECE Department - 2021 Regulation | 2nd Semester ECE Dept 2021 Regulation