When I derive eq 1.4 I don't get the minus sign in front of it. This is why I consider Na=Nd (concentration of dopants). Indeed from the plot 1.a I see at x=xn Nd=-axn>0 and at x=xp Na=axp>0. Is there another reason for the minus sign or should I consider Na=-Nd?
Thank you in advance! Best regards Alessandro Andreotti
PS: In Q1.5 it's written er=11.0 Did you mean 110 or 11 is correct?
One curiosity about the band diagram in Q2 what does the energy line Evac represent?