A Si pn-junction, in the p-region NA= 107 cm, Dn = 39 cm/sec, tn=1 psec and in the n-region No = 5x10 cm, D=12 cm/sec, tp = 1 psec .The cross section area A = 20m x 50m and T=300K. a) Calculate the junction built-in voltage Vo. b) If VF = 0.8 Vo : (i) calculate the excess carriers concentration at the edges of the depletion region. (ii) calculate the current due to holes Ip (iii) calculate the current due to electrons In. c) If this junction is to be used as the emitter- base of a PNP BJT calculate the injection efficiency YE d) If this junction is to be used as the emitter-base of a NPN BJT with the n-region as the emitter, calculate the injection efficiency YE e) Should the BJT be a good PNP or NPN?. Explain your choice. M .