Electrical Properties
Chapter Name : The Solid State |
Sub Topic Code : 102_12_01_11_02 |
Topic Name : Electrical Properties |
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Sub Topic Name : Conduction Of Electricity In Semi-Conductors |
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Introduction
• In case of semiconductors, the gap between the valence band and conduction band is small. Therefore, some electrons may jump to conduction band and show some conductivity. • Electrical conductivity of semiconductors increases with rise in temperature, since more electrons can jump to the conduction band. • Substances like silicon and germanium show this type of behavior and are called intrinsic semiconductors. • Their conductivity is increased by adding an appropriate amount of suitable impurity. This process is called doping.
Pre-Requisites:
Periodic table, elements, chemical Properties
Activity:
• Diode is a combination of n-type and p-type semiconductors and is used as a rectifier. • Transistors are made by sandwiching a layer of one type of semiconductor between two layers of the other type of semiconductor.
Real Life Question:
Where does chlorine gas come from?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| group | Group is the vertical column on the periodic table which contains elements having the similar properties. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| transistors | • Diode is a combination of n-type and p-type semiconductors and is used as a rectifier. • Transistors are made by sandwiching a layer of one type of semiconductor between two layers of the other type of semiconductor. |
Real life uses :
• Diode is a combination of n-type and p-type semiconductors and is used as a rectifier. • Transistors are made by sandwiching a layer of one type of semiconductor between two layers of the other type of semiconductor.
Places to visit :
Electronic gadgets.
Practical examples around us
| Examples | Explainations |
|---|---|
| transistors | • Diode is a combination of n-type and p-type semiconductors and is used as a rectifier. • Transistors are made by sandwiching a layer of one type of semiconductor between two layers of the other type of semiconductor. |
What you learn in Theory:
• In case of semiconductors, the gap between the valence band and conduction band is small. Therefore, some electrons may jump to conduction band and show some conductivity. • Electrical conductivity of semiconductors increases with rise in temperature, since more electrons can jump to the conduction band. • Substances like silicon and germanium show this type of behavior and are called intrinsic semiconductors. • Their conductivity is increased by adding an appropriate amount of suitable impurity. This process is called doping.
What you learn in Practice:
• Semiconductors can conduct electricity when they are doped.