Problem $7\mathrm{.}16(10$ points$)$ An abrupt silicon pn junction at T $=300$ K has impurity doping concentrations of Na $=5$ x $1016$ cm$3$ and Nd $=1015$ cm$3.$ Calculate $($a$)$ Vbi, $($b$)$ W at $($i$)$ VR $=0$ and $($ii$)$ VR $=5$ V$,$ and $($c$)|$Emax$|$ at $($i$)$ VR $=0$ and $($ii$)$ VR $=5.$