4. A Si P*N diode is doped with NA (NA>> n;) in P and Np (Np>> n;) in N. The resistivity of the N- region is 1 Ocm. What would be the resistivity of the P-region if 99% of the total width of the space charge region would be located on the N side? Assume carrier mobilities do not change with the doping density and u,= 1500, up=500.

Consider an idealized diode with a reverse saturation current 0.01 mA and an abrupt turn-on voltage of 0.7 V (assume no breakdown and operation away from the knee of the diode curve). For the circuit shown, both resistors are 100 2, the constant source is Vp = 5 V, and the time-dependent source is V3 = 20 sin(at) V. Calculate (a) the peak positive voltage V and the associated current through the diode and (b) the peak negative voltage V and the associated current through the diode. Rulamting R Vs + > KHI

2. Given a Si diode with the following physical ch/s the doping concentration in the p-type is 2.25x10" em" and in the n-type is 2.25x10"cm", junction area is 2x10° em', life time of hole in n-region-10 us, life time of electron in p-region -50 us, hole and electron mobility's are 600 em'v's' and 2100 cm'v's" respectively, the intrinsic carrier concentration is 1.4x10" cm und the voltage is 0.66 v operation at room temperature. Calculate Jo and Ju, then calculate the total diode current.

A germanium pn junction diode was fabricated on a wafer with doping concentration of 7.8 x 105 cm3. The p-region was created by doping 1018 cm using ion-implantation. Compute the following: barrier potential ii. i. depletion width at the junction. If this diode has saturation current Io-15 nA at 300 K, what is the diode current if potential across the diode is 0.8 V (n=1). 111.