Yes. The npn transistor uses ideas that are very smart. The grounded
emitter is silicon doped with arsenic with high concentraction and the
next silicon section , base, is oppositely doped with boron to make a
pn diode with the emitter. When a diode is forward biased, mobile
carriers flow with an advantageous amount ratio : the p base sends
fewer positive holes into the emitter than the n emitter sends
electrons into the base. Amplification is explained in those two
flows : few holes from the base create a large flow of electrons from
the emitter. So a small base current is amplified into a large
electron current : AMPLIFICATION ! The collector is lightly doped and
electrons fromthe emitter diffuse into the collector after crossing
the thin base. This collection allow "charge neutrality" to continue
for years, if the temperature remains below 125 degrees celsius. If
the transistor gets too hot several failure mechanisms destroy this
amplifired.
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