Problem $6(15\%)$

$($a$)$ The following currents are measured in a uniformly doped npn bipolar

transistor.

I$\_($nE$)=0\mathrm{.}50$mAI$\_($pE$)=3\mathrm{.}5\backslash$mu A

I$\_($nC$)=0\mathrm{.}495$mAI$\_($R$)=5\mathrm{.}0\backslash$mu A

I$\_($G$)=0\mathrm{.}50\backslash$mu AI$\_($pc$0)=0\mathrm{.}50\backslash$mu A

Determine the following current gain parameters: $($i$)\backslash$gamma $,($ii$)\backslash$alpha $\_($T$),($iii$)\backslash$delta $,($iv$)\backslash$alpha $,$

and $($v$)\backslash$beta $.($b$)$ If the required value of common$-$emitter current gain is $\backslash$beta $=120,$

determine new values of I$\_($nc$),$I$\_($pE$),$ and I$\_($R$)$ to meet this specification assuming

$\backslash$gamma $=\backslash$alpha $\_($T$)=\backslash$delta $.$

I$\_($nE$)$ : Electron current in the emitter.

I$\_($nC$)$ : Electron current in the collector.

I$\_($pE$)$ : Hole current in the emitter.

I$\_($G$)$ : Due to the generation of carriers in the reverse$-$biased B$-$C junction.

I$\_($R$)$ : Due to the recombination of carriers in the forward$-$biased B$-$E junction.

I$\_($pc$0)$ : Due to the diffusion of minority carrier holes in the collector.