1. Semiconductor Materials
Submitted by: Arabi Radwan
Submitted by: karim ahmed abu amo

2. Semiconductors
• Introduction
• Definition & Function
• Formation or production
• Crystal structure
• Application

3. Introduction
Conductor: allow current to flow
because they are made of
materials with abundant of
free electron.
Insulator: restrict current to flow
because they have small
numbers of free electron.
Semiconductor :have enough
electrons to allow some
current to flow but not enogh
to allow so easily.

4. Electrical conduction is the result of
electron motion within each band
For a conductor, conduction bands and valence bands are not
separated and there is therefore no energy gap. The conduction
band is then partially occupied (even at low temperatures),
resulting in a “high” electrical conductivity.

5. What is a Semiconductor
 A semiconductor is a material that has
intermediate conductivity between a
conductor and an insulator
 Also called "III-V" materials since
semiconductor elements are in
groups III and V of the periodic table
of chemical elements.
Examples are silicon (14Si),
germanium(32Ge)

6. Doping
• Doping : is the addition of
minute quantities of non-
silicon material to
semiconductor.
• This added material
changes the number of
vailable free electron .
• Doping process produces
two groups of
semiconductors: the
negative charge conductor
(n-type) and the positive
charge conductor (p-type)

8. N-type and P-type
• As (phosphorus), a Group V
element, introduces conduction
electrons and creates N-type
silicon (called a Donor).
• B (Boron), a Group III element,
introduces holes and creates P-
type silicon, and is called an
acceptor.

9. Production-

10. Examples
 Diode: A one way
valve
 Allow current to
flow in only one
direction
 Transistor: Electronic
Switch

11. Types of Diodes
 Power diode (500-1000
Volt)
 Used in power circuits
 Zener Diode
 Allow current to flow in
reverse biased(only at specific
volt)
 Light emitting diode(LED)
 Used in automobile
 Required (1.5 -2 volt 30 mA)

12. Diode
 Schematic symbol
 How it works
Anode Cathode

13. Reversing polarity
of the power source

14. Applications
• Power diode
• (AC to DC converter)
half wave rectifier

15. Full wave rectifier(power supply)

16. Function
 Semiconductors act as an electrical conductor
or insulator depending on chemical alteration
 It also control and amplify current or volt
using a small voltage or current.
 Examples:
 Diode: allow or restrict current to flow
 Transistors: Amplifying

17. Automotive alternator
• Battery charging
• Six diodes
(rectifier Bridge)

19. Transistors

20. Analogy
• Use a low current to
control a higher current
• Act as a switch or gate
for electronic circuit.
• Used as an amplifier

21. Amplification

22. Applications

23. Diode
 Schematic symbol
 How it works
Anode Cathode

24. Functions
Semiconductor devices control and amplify
because a small voltage or current, allows the
semiconductor to pass or block electrical
current.
Devices can be fabricated with other
capabilities such as passing electric current in
only one direction, emitting light, mixing and
transforming signals, etc.