[...]... Intrinsic silicon (or germanium) must be modified by increasing the number of free electrons or holes to increase its conductivity and make it useful in electronic devices This is done by adding impurities to the intrinsic material Two types of extrinsic (impure) semiconductive materials, n-type and p-type, are the key building blocks for most types of electronic devices After completing this section, you... Crystal Hole Doping PN junction Barrier potential Study aids for this chapter are available at http://www.pearsonhighered.com/electronics INTRODUCTION Electronic devices such as diodes, transistors, and integrated circuits are made of a semiconductive material To understand how these devices work, you should have a basic knowledge of the structure of atoms and the interaction of atomic particles An important... Amplifier Frequency Response 505 1 Introduction to Electronics 2 10 Answers to Odd-Numbered Problems Glossary Index 944 951 931 This page intentionally left blank C ONTENTS 1 1–1 1–2 1–3 1–4 1–5 2 2–1 2–2 2–3 2–4 2–5 2–6 2–7 2–8 2–9 2–10 3 3–1 3–2 3–3 3–4 3–5 3–6 4 4–1 4–2 4–3 4–4 4–5 4–6 Introduction to Electronics 1 The Atom 2 Materials Used in Electronics 7 Current in Semiconductors 11 N-Type and... watching or listening to someone else Only hard work and critical thinking will produce the results you expect and deserve Acknowledgments Many capable people have contributed to the ninth edition of Electronic Devices It has been thoroughly reviewed and checked for both content and accuracy Those at Prentice Hall who have contributed greatly to this project throughout the many phases of development... are characterized by atoms with four valence electrons Silicon is the most commonly used semiconductor Band Gap FYI Next to silicon, the second most common semiconductive material is gallium arsenide, GaAs This is a crystalline compound, not an element Its properties can be controlled by varying the relative amount of gallium and arsenic GaAs has the advantage of making semiconductor devices that respond... semiconductive material? Why does a semiconductor have fewer free electrons than a conductor? How are covalent bonds formed? What is meant by the term intrinsic? What is a crystal? S EMICONDUCTORS The way a material conducts electrical current is important in understanding how electronic devices operate You can’t really understand the operation of a device such as a diode or transistor without knowing something... helping to make this edition the best one yet Gary Snyder created the circuit files for the Multisim® features in this edition Gary also wrote Chapter 18, Basic Programming Concepts for Automated Testing I wish to express my appreciation to those already mentioned as well as the reviewers who provided many valuable suggestions and constructive criticism that greatly influenced this edition These reviewers... Because the trivalent atom can take an electron, it is often referred to as an acceptor atom The number of holes can be carefully controlled by the number of trivalent impurity atoms added to the silicon A hole created by this doping process is not accompanied by a conduction (free) electron Majority and Minority Carriers Since most of the current carriers are holes, silicon (or germanium) doped with... – ᮤ + V Another type of current occurs in the valence band, where the holes created by the free electrons exist Electrons remaining in the valence band are still attached to their atoms and are not free to move randomly in the crystal structure as are the free electrons However, a valence electron can move into a nearby hole with little change in its energy level, thus leaving another hole where it... the valence band is produced by valence electrons, it is called hole current to distinguish it from electron current in the conduction band As you have seen, conduction in semiconductors is considered to be either the movement of free electrons in the conduction band or the movement of holes in the valence band, which is actually the movement of valence electrons to nearby atoms, creating hole current . Data Floyd, Thomas L. Electronic devices : electron flow version / Thomas L. Floyd. — 9th ed. p. cm. Includes index. ISBN-13: 978-0-13-254985-1 (alk. paper) ISBN-10: 0-13-254985-9 (alk. paper) 1. Electronic.