DIODE

Question 1

A ____ is a device that conducts
current only in one direction. It is
formed by doping a one part of an
intrinsic semiconductor by a
trivalent material and the other
part by a pentavalent material.

Answer 1

diode

Question 2

The boundary between the two
extrinsic part is called the

Answer 2

PN
junction.

Question 3

At the instant that a PN junction is formed, the free electrons near the junction in the n region begins to diffuse across the junction into the p region where they combine with
the holes near the junction. The _____ loses free electrons ____ near the junction

while the _______ as the electrons and holes combine near the junction. This two layers form the _______.

Answer 3

n region loses free electrons, layer of
positive charge

p region loses holes, creating a layer of negative charge

depletion region.

Question 4

The depletion region contains ions of
opposite charges and there is a force
acting on them stated by

Answer 4

Coulumb’s Law

Question 5

The forces between the layers form
a field of force called an

Answer 5

electric field.

Question 6

The _____ is a barrier to the free
electrons in the n region.

Answer 6

electric field

Question 7

Barrier
Potential or Threshold Voltage

Answer 7

is the
amount of voltage required to move a
free electron towards the electric field.

Question 8

N region has _______
level than P region.

Answer 8

slightly lower energy

Question 9

At the instant the PN junction is
formed, the free electrons from the
conduction band of the n region
diffuses across the junction and
temporarily become a free electron
of the p region but quickly losses
energy and

Question 10

The conduction band of the n region
decreases energy level due to the
diffusion of higher energy electron
across the junction. The junction
will be at equilibrium when the
depletion region is complete and the
diffusion stops. The energy gradient
across the depletion