GATE 2017 EC – Question 48

As shown, two Silicon (Si) abrupt $p$-$n$ junction diodes are fabricated with uniform donor doping concentrations of $N_{D1} = 10^{14}$ cm$^{-3}$ and $N_{D2} = 10^{16}$ cm$^{-3}$ in the $n$-regions of the diodes, and uniform acceptor doping concentrations of $N_{A1} = 10^{14}$ cm$^{-3}$ and $N_{A2} = 10^{16}$ cm$^{-3}$ in the $p$-regions of the diodes, respectively. Assuming that the reverse bias voltage is $\gg$ built-in potentials of the diodes, the ratio $C_2/C_1$ of their reverse bias capacitances for the same applied reverse bias, is ________.