Q$.7$

An abrupt Si p$-$n junction with cross$-$sectional area $\backslash (\backslash$mathrm$\{$A$\}=0\mathrm{.}01\backslash$mathrm$\{$~cm$\}^\{2\}\backslash )$ has the following properties at $300$ K:

$\backslash [$

$\backslash ]$

$($a$)$ Please draw diagrams to illustrate the effects of forward and reverse biases at a $\backslash ($ p $\backslash )-\backslash ($ n $\backslash )$ junction on the transition region width, electrostatic potential and energy band.

$($b$)$ Given that the forward current $\backslash ($ I $\backslash )$ of the $\backslash ($ p$-$n $\backslash )$ junction is $0\mathrm{.}16$ mA $,$ please calculate the forward bias $\backslash ($ V$\_\{$F$\}\backslash ).$

$($c$)$ Assume the p$-$n junction in part $($a$)$ is used as a solar cell with photocurrent $\backslash ($ I$\_\{\backslash$mathrm$\{$L$\}\}=25\backslash$mathrm$\{$~mA$\}\backslash ).$ Sketch the current$-$voltage $(\backslash ($ I$-$V $\backslash ))$ characteristic graph of the p$-$n junction solar cell, including the calculated numerical values of $\backslash ($ V$\_\{\backslash$mathrm$\{$oc$\}\}\backslash )$ and $\backslash ($ I$\_\{\backslash$mathrm$\{$sc$\}\}\backslash )$ points. Briefly describe the future trends of developing solar cells?