I had a look at problem 17.2 in your book and had some problems with it: 'Estimate the bandgap for the semiconductor and the concentration of donor ions'.
I think the problem refers to footnote 20:
- Case 1/T large => I=0 => n=D, p=0, thus the density of donor ions is about 2.5*10^(19) /m^3
- Case 1/T small, but not near to 0: n=I and thus the equation on the left side in the diagrame should be ln(n)=-B*E_gap + constant and thus, the slope of the line is equal to E_gap/k_B
Are these answers correct?
I believe this problem is also in the problem sets, but our tutor refused to go through them in tutorials. I was in your revision lecture this morning and you mentioned that there are usually 1-2 tutors who do that. I know a second or third one...