1. Basic Electronics (EC1101) Introduction to Semiconductors
By: 1107_003
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2. TOPICS TO BE COVERED Introduction Historical Background
Physical Properties

3. LEARNING OBJECTIVE Students should be able to:
List and relate important historical events related to semiconductors
Explain the concept of unilateral conduction
List the important properties associated with semiconductors

4. INTRODUCTION Semiconductors Unilateral conduction resistor
p-n junction diode
tap i i

5. HISTIRICAL BACKGROUND
unilateral conduction of crystals.
Germanium (Ge) diode
Germanium (Ge) transistor
relatively easy to find,
available in fairly large quantities, and
easy to refine to obtain very high levels of purity.

6. INTRODUCTION 1954 - Silicon (Si) transistor
less temperature sensitive, and
it is available in abundance.
early 1970’s - Gallium arsenide (GaAs) transistor
GaAs transistor had speeds of operation up to five times that of Si.

7. PHYSICAL PROPERTIES
Conductivity: Electrical conductivity is a measure of a material's ability to conduct an electric current.
Temperature coefficient of resistance: Change in the resistance offered by a material to the flow of electrons through it changes with change in temperature.
Property Material
Metals
Semiconductors
Insulators
Conductivity (σ)
unit (S m −1 ) −6
10 − −19
temperature coefficient
Positive
(PTC)
Negative
(NTC)
(at v. high temp.)

8. Image Credits
Image of tap: parts.html

9. REFERENCES Wikipedia - https://en.wikipedia.org/wiki/Main_Page
Electronic Devices & Circuit Theory (11e)
by R. L. Boylestad & L. Nashelsky
of Pearson Education
Electronic Devices and Circuits (2e)
by B. P. Singh & R. Singh