Chapter 3 Lecture - Part 5

Known the text derives an expression for the hall the

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: lectrons in the y At direction will equal zero and no deflection of the current will occur. current – Electrodes at either side of the SC can be used to Electrodes measure the voltage resulting from Ey otherwise measure known as the Hall voltage. known – The text derives an expression for the Hall The coefficient, which is the inverse of the hole concentration times the charge. concentration The Hall Effect The Hall effect - graphically The Fermi Level at Equilibrium The • General Rule: No discontinuities or gradients can General exist in the equilibrium Fermi Level. exist • Illustration – Two different materials in intimate contact • No external fields or thermal gradients so no net charge flow – As such energy is conserved, so electrons moving from As one material to the other are countered with equivalent electrons going the other way (charge balance) electrons – Analysis of filled and empty states in each material Analysis using Fermi-Dirac statistics will show that (with a bit of algebra) f(E1) = f(E2). algebra) ). – Recall that a filled state is represented by f(E) and thus an empty Recall state by 1- f(E). state – This requires that EF1 = EF2 The Fermi Level at Equilibrium Two materials in intimate contact at equilibrium. Since the net motion of electrons is zero, the equilibrium Fermi level must be constant throughout....
View Full Document

Ask a homework question - tutors are online