Physics of Semiconductor Devices

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Carrier generation

About one in every 1012 carbon atoms is the radioactive isotope 14C. This isotope decays by β decay with a lifetime of 5730 years. This corresponds to about 3000 nuclear decays in your body per second. Semiconductors are also affected by the naturally occuring radioactivity all around us.

A 7 Mev α-particle strikes a silicon crystal and loses its energy by generating photons, phonons, and electron-hole pairs. The conductivity of the semiconductor is temporarily increased until the electrons and holes recombine by emitting photons and phonons. Assuming that 30 % of the α-particle energy is used to generate electron-hole pairs, how many pairs are created?

N =