PN Junction Devices
Subject and UNIT: Electron Devices and Circuits: Unit I: PN Junction Devices
• It is seen that in conductors current flow is due to the free electrons. When conductor is subjected to an external voltage, free electrons move from negative to positive terminal with a steady velocity constituting a current.
PN Junction Devices
Subject and UNIT: Electron Devices and Circuits: Unit I: PN Junction Devices
• When a voltage is applied to a semiconductor, the free electrons try to move in a straight line towards the positive terminal of the battery. The electrons, moving towards positive terminal collide with the atoms of semiconductor and connecting wires, along its way.
Subject and UNIT: Electron Devices and Circuits: Unit I: PN Junction Devices
The two type of materials namely p-type and n-type are chemically combined with a special fabrication technique to form a p-n junction.
Electron Devices and Circuits
Subject and UNIT: Electron Devices and Circuits: Unit I: PN Junction Devices
Electron Devices and Circuits: Unit I: (b) PN Junction Devices : Syllabus, Contents
Extrinsic Semiconductors
Subject and UNIT: Electron Devices and Circuits: Review of Semiconductor Materials (Pre-requisite)
• When a small amount of trivalent impurity is added to a pure semiconductor, it is called p-type semiconductor. The trivalent impurity has three valence electrons. These elements are such as gallium, boron or indium. Such an impurity is called acceptor impurity.
Extrinsic Semiconductors
Subject and UNIT: Electron Devices and Circuits: Review of Semiconductor Materials (Pre-requisite)
When a small amount of pentavalent impurity is added to a pure semiconductor, it is called n-type semiconductor. The pentavalent impurity has five valence electrons. These elements are such as arsenic, bismuth, phosphorous and antimony. Such an impurity is called donor impurity.
Types
Subject and UNIT: Electron Devices and Circuits: Review of Semiconductor Materials (Pre-requisite)
• Depending upon the type of impurities, the two types of extrinsic semiconductors are, 1. n-type and 2. p-type
Subject and UNIT: Electron Devices and Circuits: Review of Semiconductor Materials (Pre-requisite)
A sample of Semiconductors in its purest form is called an Intrinsic Semiconductor. The impurity content in Intrinsic Semiconductor is very very small, of the order of one part in 100 million parts of Semiconductor.
Classification of Materials | Semiconductor Materials
Subject and UNIT: Electron Devices and Circuits: Review of Semiconductor Materials (Pre-requisite)
• We have seen that every shell is associated with an energy level. An electron orbiting very close to the nucleus in the first shell is very much tightly bound to the nucleus and possesses only a small amount of energy.
Semiconductor Materials
Subject and UNIT: Electron Devices and Circuits: Review of Semiconductor Materials (Pre-requisite)
• The matter which occupies the space may be solid, liquid or gaseous. The molecules and atoms, of which all the substances are composed, are not at all elements but are themselves made up of simpler entities.
Electron Devices and Circuits | Introduction
Subject and UNIT: Electron Devices and Circuits: Review of Semiconductor Materials (Pre-requisite)
• The materials such as copper, aluminium etc. are good conductors of electricity. While the materials such as wood, glass, mica etc. are very bad conductors of electricity and are called insulators.
Sorting and Searching Techniques | C Programming and Data Structures
Subject and UNIT: C Programming and Data Structures: Unit V: Sorting and Searching Techniques
C Programming and Data Structures: Unit V: Sorting and Searching Techniques : Two Marks Questions with Answers