A silicon p$-$n junction diode is fabricated with the following parameters: N$!=10"$#cm$$\%,$ N& $=10"\text{'}$cm$$\%.$ the intrinsic carrier concentration is n$(=1\mathrm{.}510")$cm$$\%$ at $300$K$.$ and the electron and hole mobility are $*=1350$cm$+/$V $$ s$,,=480$cm$+/$V $$ s respectively. Junction across area is $0\mathrm{.}01$ cm$+$; the electron lifetime in the p$-$region: $*=1$s$,$ the hole lifetime in the n$-$region: $,=2$s$.$ a$)$ calculation the diffusion coefficient for electron and hole $($based on Einstein relationship$)$ b$)$ calculate the building voltage across the depletion region. c$)$ calculate the current at biases including: $-0\mathrm{.}1$V$,0\mathrm{.}3$V and $0\mathrm{.}7$V