In this course, we will explore the electrical properties of materials and classify different materials as conductors, semiconductors or insulators. We will look at some examples of conductors, semiconductors and insulators, and note the key factors that cause the differences in their electrical properties. We will use rudimentary band theory to show how temperature impacts the conductivity of the three classifications of materials. We will learn what causes the differences in electrical behavior of a p-type versus an n-type semiconductor in a p-n diode.