Tunnelling Probability of 2.1eV Electron on 3.1eV Barrier

[rgalvan2]

Homework Statement

An electron of energy E = 2.10 eV is incident on a barrier of width L = 0.67 nm and height Vo = 3.10 eV

What is the probability that the electron will pass through the barrier?

Homework Equations

I know that T=Ge^-2KL.
K=2pi*sqrt((E-Uo)/1.505eVnm^2))
G=16*(E/Uo)*(1-(E/Uo))

The Attempt at a Solution

K=5.12nm^-1
G=3.5
T=3.5*exp(-2*(5.12nm^-1)*(.67nm))
nm cancels in the exponent so:
T=3.5*exp(-2*5.12*.67)=3.5*.001=.35%
This isn't the right answer though. I've tried 3.5,
35, .035, and .0035 and none of these answers are right. Any help? Thanks!

 

[cipher42]

If you're looking for the probability that it tunnels, that should be |T|^2, not just T (remember, all of the physical significance of the wave function has to do with it's absolute magnitude)