The junction capacitance Cj of a one-sided silicon pn junction (i.e. one side of the junction is highly doped, the other side is much lower doped, e.g. n+p or p+n) at T = 300 K is measured under a reverse bias VA = - 50 mV and found to be 1.3 pF. The junction area is 10-5 cm^2 and Vbi = 0.95 V.
(a) Find the doping concentration of the low-doped side of the junction.
(b) Find the doping concentration of the higher doped region.