Lesson: Doped Semiconductors Physics • 9th Grade

In this lesson, we will learn how to describe the effect that doping a semiconductor has on its electrical properties.

Lesson Plan

Students will be able to

describe how adding donor and acceptor ions to a pure semiconductor’s atomic lattice produces free electrons and vacancies in the lattice,
relate the free electron and vacancy densities of a doped semiconductor using the formula ,
relate the free electron and vacancy densities to the acceptor and donor ion densities in a doped semiconductor using the formulas ,
relate the free electron and vacancy densities to the acceptor and donor ion densities in a doped semiconductor using the formulas .

Lesson Video

Lesson Explainer

Sample Question Videos

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Lesson Worksheet

Q1:

A doped semiconductor that contains acceptor ions and is at thermal equilibrium is modeled using three variables. The density of free electrons in the semiconductor is represented by . The density of acceptor ions in the semiconductor is represented by . The density of vacancies in the semiconductor is represented by . Which of the following formulas correctly represents the relationship between these variables in the semiconductor?

Q2:

The diagram shows a lattice of silicon atoms that contains one atom of phosphorus. One of the electrons from the outermost shell of the phosphorus atom moves freely in the lattice. What is the net relative electronic charge of the phosphorus?

Q3:

A doped semiconductor that contains donor ions and is at thermal equilibrium is modeled using three variables. The density of free electrons in the semiconductor is represented by . The density of donor ions in the semiconductor is represented by . The density of vacancies in the semiconductor is represented by . Which of the following formulas correctly represents the relationship between these variables in the semiconductor?