Problem $7$

$($PN junction under bias$)$

A silicon step junction has uniform impurity doping concentrations of $N_A=5{10}^{15}c{m}^{-3},$ and $N_D=1{10}^{15}c{m}^{-3}$ and a cross$-$sectional area of $A={10}^{-4}c{m}^2.$ Let ${}_n=0\mathrm{.}4{10}^{-6}s,{}_n=1350c\frac{m^2}{V}-s,$ and ${}_p=0\mathrm{.}1{10}^{-6}s,{}_p=480c\frac{m^2}{V}-s.$ Calculate the electron current at $x=x_n+\frac{1}{2}{L}_p$ for $V_a=\frac{1}{2}{V}_{bi}.$

$\backslash$table$[[$number$,$example $(A)$

what is the answer in example?