Exercise 2.3.5-1

Show the equality of the two equations for the minority carrier density

	The two equations for the minority carrier concentration (here the electrons at the p-side) at the edge of a junction were
		npe(U) ÷ ÷ edge SCR  =  nne(U) ÷ ÷ edge SCR  · exp –   Vn + U kT npe(U = 0)  =  ni2 nph(U = 0)
	The first equation came from simply relating one kind of carriers on both sides of the junction including non-equilibrium (i.e. voltage U not zero), the second one is simple the mass action law valid for equlibium (i.e. U = 0).
		Show that the two equations are identical.
		Hint: Express nne in terms of nph. Write down the equation for nph and reshuffle the energies in the exponent so that nne and ni can be extracted.
	Link to the solution

To index

2.3.5. Junction Reconsidered

Solution to Exercise 2.1-1 Free Electron Gas with Constant Boundary Conditions

Solution to 2.3.5-1

© H. Föll (Semiconductor - Script)