Electronics: Semiconductors

Caupayan,JeddaAnne G. BSEd-4

Semiconductors

I. Introduction

Our prior knowledge tells us that conductors are materials that allow the flow of electric current in one or more directions. We also know that insulators cannot conduct electricity but there is a certain material that can be partly an insulator and conductor and that is semiconductor. This chapter will tell us about semiconductor, its types and applications.

II. Definition

Semiconductors are materials whose ability to conduct electricity falls somewhere between that an insulator and that of a conductor. Those are actually solid chemical elements that can conduct electricity under some conditions but not others, making it a good material for the control of electrical current. Semiconductors are used for electrical devices because their material characteristics can be changed significantly through the process called doping. Doping is s process of adding very small amounts of selected conductive additives called impurities to semiconductors. It can increase the number of free charges. When an impurity increases the number of free electrons, the doped semiconductor is negative or n-type, but when it reduces, causing more holes, it creates appositive or p-type semiconductor.

III. Types of Semiconductors

1. 1. Intrinsic semiconductor

-a chemically very pure and possesses poor conductivity

-has equal number of carriers (electrons) and positive carriers (holes)