Class 12 Physics — Chapter 6: SEMICONDUCTOR ELECTRONICS: MATERIALS, DEVICES AND SIMPLE CIRCUITS

What you'll learn

• ▸Energy Bands and Classification of Solids
• ▸Intrinsic and Extrinsic Semiconductors
• ▸N-type and P-type Semiconductors
• ▸The p-n Junction and Depletion Region
• ▸Diode Biasing and V-I Characteristics
• ▸Application of Diode as a Rectifier
• ▸Special Purpose Diodes
• ▸Bipolar Junction Transistor (BJT)
• ▸Transistor as an Amplifier and Switch
• ▸Digital Electronics and Logic Gates

Chapter Summary

--- PAGE 1 --- Chapter Fourteen SEMICONDUCTOR ELECTRONICS: MATERIALS, DEVICES AND SIMPLE CIRCUITS 14.1 INTRODUCTION Devices in which a controlled flow of electrons can be obtained are the basic *building blocks* of all the electronic circuits. Before the discovery of transistor in 1948, such devices were mostly vacuum tubes (also called valves) like the vacuum diode which has two electrodes, viz., anode (often called plate) and cathode; triode which has three electrodes – cathode, plate and grid; tetrode and pentode (respectively with 4 and 5 electrodes). In a vacuum tube, the electrons are supplied by a heated cathode and the controlled flow of these electrons in *vacuum* is obtained by varying the voltage between its different electrodes. Vacuum is required in the inter-electrode space; otherwise the moving electrons may lose their energy on collision with the air molecules in their path. In these devices the electrons can flow only from the cathode to the anode (i.e., only in one…

Practice Questions from this Chapter

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1. Explain how semiconductors work. Get Solution →
2. Define what a transistor is. Get Solution →
3. List common electronic devices. Get Solution →
4. What were the basic building blocks of electronic circuits before the discovery of transistors in 1948? Get Solution →
5. According to the text, which of the following are examples of elemental semiconductors? Get Solution →
6. In the energy band theory of solids, what is the energy band that includes the energy levels of the valence electrons called? Get Solution →
7. How many valence electrons does a silicon (Si) or germanium (Ge) atom have? Get Solution →
8. What is the name for the energy gap between the top of the valence band and the bottom of the conduction band? Get Solution →

Did you know?

• 💡 Sand is mostly silicon dioxide, a material crucial for making computer chips.
• 💡 The invention of the transistor made electronic devices small enough to fit in your pocket.
• 💡 Early computers used thousands of huge, hot vacuum tubes and filled entire rooms.
• 💡 Ancient civilizations used natural crystals like galena to detect radio waves long ago.
• 💡 Your smartphone contains billions of tiny semiconductor switches called transistors.

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