Accurate determination of bandgap narrowing in heavilydoped epitaxial p-type silicon

Bandgap narrowing in p-type epitaxial silicon uniformly doped with boron in the concentration range 2×10¹⁷ to 5×10¹⁸cm¿3 is evaluated from the temperature dependence of the collector current of npn bipolar transistors. The study is focussed on the sensitivity of the extracted bandgap narrowing to the model used to describe the intrinsic carrier concentration in pure silicon.