Question $\backslash$# $6/6$: HBT $(10$ Points$)$

Consider the following $\backslash ($ P N P $\backslash )$ hetero$-$junction bipolar transistor $($HBT$).$

Draw $($on the grid next page$)$ the band diagram of the $\backslash ($ P N P $\backslash )$ HBT in the normal mode. Assume the emitter base junction is forward biased with $0\mathrm{.}2$ V and the collector$-$base junction is reverse biased with $0\mathrm{.}3$ V $.$

The band diagram must be drawn to scale. Assume that the potential drop is equally distributed on both side of each junction. Your band diagram should include:

$-$ the fermi levels

$-$ the local vacuum level

$-$ the depletion charge $(+$ or $-)$ in the forbidden band

$-$ the conduction band edge

$-$ the valence band edge