1. (Streetman 7th 5.22 modified) The electron injection efficiency of ajunction is y=I/ at xp =0. a. Assuming that the junction follows the simple diode equation,express II in terms of

the diffusion constants, diffusion lengths,and equilibrium minority carrier concentrations. c. Design a pn junction (by choosing N, and N) so that the electron injection efficiency is > 0.99 (remember to take into account mobility changes with doping). b. Show that / can be written as [ 1 + L PpHp°/Lp° nn Ho°]}, where thesuperscripts refer to the n and p regions. What should be done toincrease the electron injection efficiency of a junction?