Register to reply

Mobility of electrons and holes

by Distr0
Tags: electrons, holes, mobility
Share this thread:
Distr0
#1
Jan9-09, 11:29 AM
P: 10
Problem:
Calculate mobilities of electrons and holes (assuming equal) in grey tin, silicon and germanium. Calculate also the mobility that would be necessary for diamond to have an intrinsic conductivity of 10-12 S m-1 if the hole and electron mobilities were equal.

Working:
[tex]\sigma[/tex] = Nc (e[tex]\mu[/tex]n*e[tex]\mu[/tex]p)exp(−Eg /2kT)

[tex]\sigma[/tex]= 10-12
e = 1.6*10 -19
k = 1.38*10 -23
T = 300K
Nc = 2.5*1025
Eg(tin) = 0.08
Eg(silicon) = 1.11
Eg(germanium) = 0.66

For tin
Rearrange to give:

[tex]\mu[/tex]np = [tex]\sigma[/tex] / 2e Nc exp(−Eg /2kT)

The exponential becomes equal to zero...

I'm quite sure i'm missing something relatively simple here but not sure what
Phys.Org News Partner Science news on Phys.org
Experts defend operational earthquake forecasting, counter critiques
EU urged to convert TV frequencies to mobile broadband
Sierra Nevada freshwater runoff could drop 26 percent by 2100
Distr0
#2
Jan9-09, 12:04 PM
P: 10
It appears i was using wrong values for the conductivity and boltzmann constant, got the correct answer now.


Register to reply

Related Discussions
Mobility of electrons Atomic, Solid State, Comp. Physics 5
Building an ion mobility spectromter General Engineering 0
Mobility of holes and electrons Electrical Engineering 3
Electron mobility in copper Introductory Physics Homework 1
Why aren't electrons considered black holes ? Special & General Relativity 18