A Si npn transistor at T = 300K has an area of 10-3
cm2 , neutral base width of 1µm, and doping
concentrations of NE= 1018 cm-3,
NB = 1017 cm-3, NC =
1016 cm-3. Other semiconductor parameters are
DB= DE =20 cm2/s, τE0=
τB0= =10-7s, and
τC0=10-6 s. Assuming the transistor is biased
in the active region and the recombination factor is unity,
calculate current for (a) VBE = 0.5V; (b)IE
=1.5 mA, (c) IB = 2µA