The equation for the bandgap energy of Si given by Eq. (23.21) is a little bit different than the
equation given here and other places. In particular you use an α = 702e-6 and β = 1108
while I’ve seen others use α = 473e-6 and β = 636. Is the equation in the book wrong?
I too have seen, in the last 10 years or so, the change to α = 473e-6 and β = 636. I don’t believe
the equation in the book is wrong (link showing both) but perhaps the change results in a little
I wrote a little MATLAB script to compare the two equations. It can be downloaded here.
Below is a comparison between the two equations for temperature changes from 200K to
400K with Eg(To) = 1.16.
For one other reference, on page 16, Fig. 6, of the third edition of Sze and Ng, “Physics of
Semiconductor Devices,” Wiley, 2007 the bandgap energy of Si is plotted for, Eg(To) = 1.169,
α = 490e-6, and β = 655.