This preview shows page 1. Sign up to view the full content.
Unformatted text preview: E
Γ e Eg=1.43eV Ec
k Ev Heavy
Hole Valence Band
Ge Si mn* 0.55mo 1.1mo GaAs
0.067mo mp* 0.37mo 0.56mo 0.48mo A Few Cau[ons • The topic of eﬀec[ve mass is more complicated than can reasonably be presented in an introductory course (treatment as tensor in higher level courses) • Make sure you know what eﬀec1ve mass to use and how to use it based upon what you are calcula1ng • Calcula[on of the carrier concentra[on uses the density of
states eﬀec1ve mass – For Silicon, the density of states eﬀec[ve mass is (mn*)3/2 = 6(mlmt2)1/2 – This comes from the 6 indirect valleys, and the ellip[cal shape of those valleys – Direct gap materials such as GaAs have a single minima, so just the eﬀec[ve mass is used • Conduc1vity eﬀec1ve mass is diﬀerent than the density of states eﬀec[ve mass for Silicon *
3 mn = ( 1
1
1
+
+)
ml mt mt • Cyclotron eﬀec1ve mass is also diﬀerent • There is further complica[on around the direct indirect crossover in a material where mul[ple valleys can be...
View
Full
Document
This note was uploaded on 03/06/2014 for the course ECE 340 taught by Professor Leburton during the Spring '11 term at University of Illinois, Urbana Champaign.
 Spring '11
 Leburton

Click to edit the document details