ESE 121 Lecture Notes - Lecture 23: Differential Signaling, A Reminder, Dielectric

• School: Stony Brook University
• Department: Electrical Engineering
• Course: ESE 121
• Professor: Jan Folkson

Document Summary

Lecture 23: diods and transistors: semiconductors are solids that form a crystal. Meaning that the atoms are in a periodic arrangement. Here we see a silicon crystal: an interesting thing happens when a crystal is formed. Each si atom has 4 valence electrons and. As the si atoms get closer to one another energy bands form. The 4 electrons from each si atom form a filled band of low energy called the valence band. The 4 empty states from each si atom form an empty band of energy states called the conduction band: these bands form because no two electrons can have exactly the same energy. The gap is measured in units of energy called the electron volt (ev). An ev is defined as the amount of energy gained by a single electron moved across a potential of one volt. Semiconductors usually have a gap of less than 3ev: there are three types of crystals.